I love scissors. I use them in my kitchen, in the laundry room, at my desk, and throughout my apartment. Yet, I rarely have a pair with me while on the go. Or, at least I rarely had a pair with me until I found the KUM Pencut.

Traditional scissors are potentially hazardous items to throw in a bag (which is why I never used to carry a pair with me). They rarely come with a sheath, and without protection the likelihood of dulling the blades, or accidentally tearing a hole in your bag (or hand) is significant.

The KUM Pencut is an ingeniously designed pair of scissors that masquerades as a pen. When folded the blades are kept hidden beneath a sturdily affixed pen cap. The pen-like form gives the impression that there is nowhere for your fingers to go, but pull the plastic sliders down and two pieces of nylon fold out creating comfortable finger holds.

Outside of being cleverly designed, the scissors are very sharp, while also having full tang blades (which gives the scissors a surprising sturdiness). With the cap on, it's very easy to mistake the scissors for just another pen that I've slipped into a pen-holder in my bag; it also means that it stays in place, and is there when I need it.

The biggest downside to these scissors is the price, but given they're sturdy build and how many conversations they've started I'm confident it's worth it.

We've had such a fantastic response to the Cool Tools Library request I mentioned on Friday that we're going to turn it into a contest (previous submissions will be grandfathered in). Feel free to submit recommended books until Monday, February 13th. The authors of the two best reviews can pick a prize from the Cool Tools Prize Pool (which has been updated with some really great prizes!)

Once more for good measure:

What's the essential book for carpenters? Metalsmiths? Landscape designers? Tailors or seamstresses? What about information design? Or sous vide? Tanning or taxidermy? Home brewing? Car repair? Bicycle frame building? The list goes on and on.

Every trade and hobby has their own bible, and we want to identify and collect them all in one place so that others may benefit.

Submit your recommendation (or request) here, post it in the comments below, or feel free to email it to editor@cool-tools.org.

-- Oliver Hulland

We bought these kids sunglasses about 2 months ago (at REI), when my son was 4 months old. Before that we had about given up going out during the day, as my son would become agitated within a few minutes of going out. Now going out of the house is one of our best times.

I was a bit concerned when buying these, figuring my son would knock the glasses out of place continually. However, after a very short period he acts like the glasses aren't even there, only complaining when they are askew.

Reviewers on Amazon have complained that the strap is too big for a 4-month old. 4-months is probably near the lower limit on age for these. We needed to adjust the strap to the smallest position and use them with a hat for them to fit. But we also found that they didn't need to be very tight to stay in place.

I bought this brand because it was carried by REI, who I believe carries quality merchandise. I'm not sure if I would trust the UV protection of the cheapest model that Walmart sources at the lowest price (poor UV protection in sunglasses being worse than no protection at all).

Besides the UV protection and ability to be out in the bright sun, there is also the cool factor, which was really unexpected. Every time we go out walking, I'm amazed at the number of turned heads and comments we get about the shades. The words "cool dude" are used frequently. I'm also now aware of the parents who are out in the bright sun with sunglasses while their infant or toddler is left to squint.

Make your own. Not those tinny flea market varieties, but large striking sonorous chimes tuned in all manner of unusual styles. (Listen to samples on the book’s website or included CD). There are several dozen unusual ways to tune the chimes. All tunings are fairly mathematical, which is the core of this book, but not difficult to execute with hardware-store tubing. My son and I used this short but very explicit manual to create a large copper pipe one that emits a lovely melody in the breeze. The bigger the better. (The bigger the more wind they need, too.) This guide is a very practical way to experience the math of music and the beauty of alternative music systems.

Setting up the hanging strings at the correct spacing.

Our copper chime hanging in the cherry tree.

In the past we've highlighted an astonishing array of useful books that covered topics ranging from bioremediation to underground home building to fermentation. These books are tools because they not only help us learn but also put knowledge to use.

Help us fortify our library of useful books by submitting your favorite text for a particular subject including an explanation of why you think it's essential. We want to feature that dog-eared book that you wouldn't lend to a friend for fear you wouldn't get it back. It can be the best beginner's guide, or a slightly more advanced technical manual detailing materials or techniques. If you can, please include scans of pages that we can use to illustrate the book's content. This has been done before but never with any insight or explanation of what makes the book useful or cool.

What's the essential book for carpenters? Metalsmiths? Landscape designers? Tailors or seamstresses? What about information design? Or sous vide? Tanning or taxidermy? Home brewing? Car repair? Bicycle frame building? The list goes on and on.

Every trade and hobby has their own bible, and we want to identify and collect them all in one place so that others may benefit.

Submit your recommendation (or request) here, post it in the comments below, or feel free to email it to editor@cool-tools.org.

When you get sick and tired of reapplying those adhesive felt furniture feet to all your furniture every time they come off (go ahead, look under something; a lot of them are coming off or missing aren't they?), you can get these improved ones that I found a few years ago.

The round metal rivet hammers easily into the end of the leg with a tack hammer, and the metal part doesn't break like the kind with the single skinny nail in the center. (And the adhesive kind, as you no doubt have noticed, do not stay properly attached for very long at all.) I have never had one of these fail yet.

This vendor has them for a good price; they have a $25 minimum, which means you have to order about 80. However, you can also get them at Amazon.

In the old days (before the web) you could not read the operating manual or instructions for an appliance, device, or tool until you got it home and unpacked it. Getting the manual was considered one of the benefits of purchasing the product. In fact, you had to purchase extra copies if you lost the original, or wanted to check it out. It was often only later when you finally had the box opened that you discovered a) it did not permit the function you bought it for, or b) it was a quarter inch smaller than it looked and so didn't fit, or c) it was incompatible with the assessors set you already had, or d) it had no manual!

Those days are gone. You can find a PDF version of the manual for most products on the web if you search hard enough. It is not as easy as it should be, but the smarter manufacturers make it easy to download the specs of whatever they sell.

That leads to this new rule: get the manual first, before you buy.

For a large home remodel I had to purchase a pile of new appliances, lights, plumbing fixtures, hardware, materials, gadgets, and some tools. I instituted a "Manual First, Buy Later" policy, and it had immediate positive effects. Once I identified a possible candidate for purchase, I would google for its manual. Equally important as finding the operating instructions and basic specs, is to get hold of the installation instructions. There are few sites that aggregate manuals and specs of major lines, but often I would wind up at the manufacturer's site. There I would download the PDF and read it carefully. That's where you find out its precise dimensions, its actual power needs, its exact connections, its real compatibility. I lost count of the number of inappropriate bad purchases I avoided by studying the manual and specs first.

What baffles me are the clueless manufacturers who still don't put their installation and operating manuals online in 2012. (I'm thinking of you, LG.) The main result of this process is simply fewer surprises. Less returns, better integration.

I was heartened to see that even the professionals do this. Here is a snapshot of our plumber "at work" in the bathroom. He has his tablet opened to a installation PDF, and his phone is googling a help number for questions brought up by specs in the PDF.

Locating any particular item's installation and operating specs is still not as easy as it should be. Amazon could make it the norm to have the full spec PDF for every item they sell, or Google could try to algorithmically sort them out, or some clever aggregator could centralize them all. But for now it is worth seeking them out first, any purchase later.

-- KK

I've had an iPhone since the first model and despite trying out probably hundreds of apps I have a relatively small collection that I use every day.

One of the things I use my iPhone for every day is catching up with blogs and news through RSS. I'm a reasonably heavy Google Reader user, following 294 feeds (including BoingBoing and Cool Tools naturally). There are a host of RSS feed reader apps in the app store, and *most* of them integrate with Google Reader. I've tried most of them, seduced by the promises of new features and pretty UIs, but I always return to one of the first I tried: Byline.

The Byline Google Reader integration is straightforward, and offers all the features you would expect. These are the same features offered by many a reader:

• Syncing of read items
• Badge showing number of unread items
• Starring and sharing (with or without notes)
• Showing all items, browsing by label or by feed
• Instapaper and mobile safari integration

And so on....

The killer feature for me, and one I've not found in any other reader app, is that Byline caches (optionally and configurably) the webpage associated with an RSS entry. That means that partial RSS entries, or feeds like Daring Fireball that link to an alternative page, have the *actual content* fully stored on the device. When travelling or somewhere without mobile internet you have full access to your RSS feeds and their precious payload of information or LOLs.

Byline isn't perfect, but every time I've tried another feed reader app I've found I can't live without the offline caching and come slinking back to byline. The *biggest* flaw with Byline was the lack of a native iPad app, but since I originally wrote this review a native iPad app was released and it works very well. Byline has only improved in stability and reliability, and I'm still using it every day. Byline coped with the Google Reader changes very well. It hasn't yet got Google + integration, but hopefully that will come soon (but it isn't core functionality anyway).

I did use the old Google Reader sharing feature to post items from reader to twitter via the shared items RSS feed. Funnily enough, despite this feature being removed from the Google Reader UI it still works in byline!