Zojirushi's Mr. Bento Lunch Jar is essentially a modern take off of a Japanese bento box. But it can keep cold things cold and hot things hot. Mr. Bento has 4 microwaveable containers: a soup container, which is watertight; a large container for your main meal that comes with an insulated lid; a smaller container I use for salads; and then an even smaller container I put cheese and grapes in. The neat thing is that all these containers stack neatly in a specified order into a main stainless jar. The way the bowls and jar are designed, they stack in a particular way so that the soup and main dish container form a seal to keep those items hot or cold, while the other two containers remain at room temperature. I have only been using my Mr. Bento a couple weeks now, but I can absolutely verify dishes stay both hot and cold, while the rest of the jar stays at room temperature. Mr. Bento even comes with a spork so you don't have to bring extra utensils - and the spork has a nice cover. Mr. Bento himself comes with a nice bag that has pockets for napkins and the like. I have found the bag is large enough to fit Mr. Bento plus an additional small plastic bowl. In my case, I typically take a small container of oatmeal to work, so I just place Mr. Bento on top and put the entire stack in the bag. Mr. Bento is certainly no paper bag, but I do not find it overly heavy. I've actually weighed it and found a fully packed Mr Bento with bag and utensil is around 3 pounds, depending how it's packed. As for how long things stay hot... well, I typically pack my lunch around 6:45 or 7 in the morning, then don't eat until 11:45 or 12, and I do not feel the need to microwave. For example, just yesterday I microwaved a frozen burrito, then cut it in half to fit it into the meal section, and made some microwaved bean soup in the soup container that was packed 7:00. At 11:00 the temperature was still good, and I did not nuke it. In fact, the burrito was hot, and steam came from the container when I opened it. Zojirushi states that all foods should be consumed within 6 hours to avoid spoilage. They also advise to preheat the jar itself with hot or cold water for maximum temperature retention, though I have never done that. Zojirushi has other Bentos, too: the Ms. and mini (and I also have their rice cooker). When you first look at Mr. Bento, you worry you're going to walk away hungry. You're mileage may vary, but I am a whopping 240 pounds of man and sometimes I wonder if I should have purchased a smaller Bento. My impetus for buying a lunch box was my discovery of spending over $100/month going out to lunch. I wanted to save money and did not want to get bored eating-in. So far so good! I also found a cult following around Mr. Bento, including the "Mr. Bento Porn" group at Flickr (ed. note: Totally Safe For Work*). This is what sold me on it.

-- Ted Boydston

Mr. Bento Lunch Jar
$47
Available from Amazon

Manufactured by Zojirushi

[*Beware: You could spend a lot of time peeping the members' awesome lunches -- sl]

Related items previously reviewed in Cool Tools:

Zojirushi Electric Dispensing Pot

How to Cook Everything

Snowpeak Stove, Cookset and Spork