The best trackball I've ever found, by far, is the sadly discontinued Logitech Trackman Marble FX, which is the conceptual predecessor to the Marble Mouse above. If you can get your hands on one (and last I check they were selling at a stiff premium on eBay) give it a try. I have 2, and I'm not parting with either.

I recently purchased one of these for problems with my wrist...

Overall, this is by far the nicest trackball I've ever used and I greatly prefer it to other types of mice for office work.

And it's cheap too!

I have matching marble mice (home and office), but still working on the optimal configuration of the secondary buttons. Currently set to cut and paste because I trackball left handed and ctrl-c ctrl-v is tough with the right hand. How do other people use them?

I''ve used a couple of the marble-sized trackballs but prefer the Kensington Expert Mouse with the larger cueball-sized ball. I've been through several generations of these (got my first in 1993 or so) and think the current model is the best so far; solidly-built and smooth, with a great scroll ring surrounding the ball that's much more ergonomic than the previous-generation's scroll wheel. I'm using 2 of these in my workstation setup at work, one for right and left hand (still trying to find a way to mirror the button setup though). I have the secondary buttons set for web-browsing--page forward and back, although I like the copy and paste idea and will give it a try.

I love this trackball (or at least it's predecessor, which Blaise mentioned above). It fits perfectly in my hand, whether working or just resting while thinking. The action is precise and smooth, and the buttons rest naturally under the clicking fingers.

Since discovering it some years ago it's all I've bought. In fact, I've finally worn out the buttons on one and I'm waiting for Amazon to ship me a new one even as a I type. Strangely, I haven't been able to find it in stores lately.

I've used trackballs since 1987. The best has been the Marble Mouse, which I bought 6 years ago. I've used it on both PCs and Macs with no problems at all. Of course, the ball has to be removed once a month for cleaning. It fits my large paws nicely and works fine while resting on my quads.

I use trackballs, ideally Logitech, on all my machines. I hate it when I have to use a mouse! Any idea why track balls are not the prefered choice everywhere ?

Sadly its a close as you can get to the Microsoft TrackBall Explorer, which is the same design with an index middle finger ball and 5 programmable buttons. I have four of these trackballs on each of my computers.

As a bonus it keeps coworkers away from my computer because they physically drag the trackball around my desk like a mouse then look up and say I can't use your mouse.

With tendinitis in my wrist, I can only use a regular mouse for a 30 min before I hurt all night long.

I use this at work and love it! My current setup is to primarily use this with my left hand, but sometimes I switch and use the right.
I also have a standard mouse attached thanks to modern computers having multiple USB ports. I use the mouse if I am in a hurry or need more precise movements.
The trackball has definately saved wear and tear on my hand/wrist/arm since I have been using it

I use this at work and a Logitech Cordless TrackMan® Optical at home. The best ever was the MS Exploroer (as stated above) but they're discontinued. The Logitech Cordless TrackMan® Optical is nearly the same. The marble mouse is fine, but it kills me not having a scroll wheel.

I use the above mentioned trackball at home on the laptop, it allows for ease of surfing while prone on your back, which you can't do with a regular mouse. For work I used a regular mouse and had great discomfort until I bought a vertical mouse. I would highly recommend it if you can't handle the trackball and still have pain.

DS Morse is right, the Microsoft TBE trumps them all. It was molded for the actual shape of a resting (right) hand, and allowed for simultaneous trackball movement and button/scroll usage without having to reposition. There is and was nothing else like it.

Unfortunately, the logitech trackballs are designed to look cool (instead of being hand-shaped), without regard to true functionality. My biggest gripe with all trackballs except the MS TBE is that you have to reposition your fingers to use the buttons ... the TBE was ingenious since the buttons and scroll were done with the thumb in a natural sideways resting position, and pointer movement done with index and middle finger.

I wish they still sold them. I have gone back to using an ultra-precise mouse for now.

I'm partial to the Kensington Expert Mouse, myself. It's not hand-shaped at all, but it's got a ring around trackball that works the same way as a thumbwheel on a modern mouse. It's awesome to be able to scroll with the flick of an index finger.

http://www.amazon.com/Kensington-Expert-Mouse-Optical-Trackball/dp/B00009KH63/ref=pd_bbs_sr_1?ie=UTF8&s=electronics&qid=1236795966&sr=8-1

I love my TrackMan Wheel and requested one as soon as I started a new job where I had to use a regular mouse.

I'm with DSMorse. I love coworkers reactions when they try to use it. :)

I've even converted my husband to it! We are a trackball only house.

I've used a trackball for nearly 15 years, going back to my Kensington turbo mouse for my Mac LCII I used at Davidson College. When I entered the corporate world, I got a variance to use a trackball over the default and crappy mice we get with our leased computers. And with the Marble Mouse an optical trackball for some years now, I've never looked back. I love these, and even do PC RTS/FPS style games with it on my gaming rig. People at LAN parties look at me strangely until they get a headshot.

My Dad uses one of these confounded gadgets. How do you track ballers scroll without a wheel? How about opening links in another tab with a single click of the wheel? I seems very inefficient for general use.

I began my love affair with the Logitech marble mouse in 2003. I have two at home and I got everyone at my office to go "marble" after they saw me using it. No more wrist problems and my hand rests on it wonderfully. I have two extras squirreled away at home.
And I never use the trackpad on my laptop either, just the marble mouse.

This is the only pointing device, short of the multi-touch pad on my macbook, that I'll use. I've learned to be able to use this device with either hand, much more easily than it would be to adjust a mouse to the left hand. I generally switch back and forth every few months to rest each hand and give myself a longer pointing life :-)

Wow. No kidding on that Trackman Marble FX, Some clown is selling one for $277!
That's ridiculous.
http://www.amazon.com/gp/offer-listing/B00000JBUI/ref=dp_olp_0?ie=UTF8&condition=all

I really like the Trackman Wheel. I like having a wheel.

I use the Logitech trackball wheel at work and home. Have had them for years. They are definitely good at keeping coworkers off your computer. I dislike using mice. It's like driving automatic after driving a stick shift for years. Plus,

Love logitech trackballs but I've had to abandon them because at 16+ hours a day on the computer, I spend a lot of time cleaning them.

i will add to the trackball only for myself.
i have some nerve damage in my cervical c spine and if i use a regular mouse i have to stop in minutes due to the pain.
on this computer i have a microsoft 1.0 trackball explorer optical .
my reclining chairs have armrests and i have them t velcro to the armrest of my recliners, one anti-gravity , one ekornes
it is a perfect fit , my hand rest on it and i can do everything by keeping my arm supported and just moving a couple fingers. it has 4 buttons and a scroll wheel.
i noticed yesterday that buy.com has a sale with rebates on the Kensington trackballs , including the expert, it is very rare one sees trackballs on sale.
Kensington also has a brand new trackball, on this page, i already received it in todays fedex, haven't had a chance to hook it up yet. it is a Kensington slimblade trackball.

I have extensive RSI in each hand, and this trackball gave me new pain.

IBM's ergonomic (right hand) optical mouse is the best pointing device for me so far.

I'm using this exact trackball right now at work, and have been for two years. I no longer have any problems with my wrist. I have nerve damage in my hands from diabetes, and using a comfortable trackball is better than medication. Really.

I've had my Logitech for years and love it. The only downside is the innards do need cleaning out every once in a while to remove the mini dustballs that accrue.

This is the best trackball you can get and it's only $20 ! All my computers at work and home do have a Logitech Marble Mouse connected to them. I also keep one on my laptop bag to use when on the go. Tip #1 : Once in a while clean the ball with Pledge and it will work like a charm. Tip #2: When using Windows I use Scroll Navigator (http://www.desksoft.com/ScrollNavigator.htm) so that I can scroll from anywhere without going to the scroll bar. For MacOSX use USB OverDrive (http://www.usboverdrive.com)

You know, I remember those. Years ago, when I first owned a computer. 386 SX loaded with DOS and Doom, I used a rollerball, and when I switched to a mouse absolutely hated it. I completely forgot all about roller balls till this post. Then I was like, 'OHHH YAHHH!' 'I remember those, those were awesome'. Then I priced them. Man, this is great, bought it on amazon, and I am rollering away even as well speak! Rollerballs are great.

It's taking me a little to get used to it. As an computer guy for the school district I have been using mice for so long, I almost forgot how to use this thing, but I am really, really loving it!

I used a trackman marble for about six years at work before switching to one of these, and i find it to be a worthy replacement (I wish i had known of the trackman's tremendous resale value back then!). For those who are susceptible to RSI, it may be a beneficial tactic to use multiple pointing devices. I use a mouse, trackball, and trackpad!

Another vote in favor of Logitech Cordless TrackMan® Optical, I have one at work and we use two at home. Better than the Marble Mouse, which I used to use and still have.

Just bought a Marble Mouse based on recommendations here, but unlike the original poster i cannot configure the small buttons for zoom. I use a Microsoft laser mouse 6000 and the small zoom button on the left side is the best thing ever for building graphics with aging eyes. Is there any way to get an identical function with this device?

As Blaise Pascal said at the top, the Trackman Marble FX has been on my desk for about a decade now, and I hope it'll be there for another decade. Why Logitech discontinued it, I have no idea.