umm i am in market for one but i dont know what they are called. its like a briefcase almost, but not nearly as thick, and just a zipper. usually you can just fit a legal pad and maybe a few pens inside. its sort of like a binder but there are no rings inside and also the material is a lot more flexible, like leather or synthetic material...i feel really dumb asking this but i have not a clue what they are....
I think its called a banana guard. It helps prevent your banana's you buy from the grocery store from going bad. It is very popular in Asian countries especially Japan. They come in various colours although yellow is the most popular since it looks like a banana. The only downside is you might mistakenly bite into the plastic banana case if you are really hungry. Like after a jog or a tough workout. I think you can buy these from Ebay or if you have a friend in Japan, maybe he can send you one or two. If you have a bunch of banana's you will need multiple banana protectors. But if you are eating a banana for lunch, you can pack it in your lunch sack and take it with you when you go to work or school. Here's a picture of what I think you are looking for:
I remember I wanted a Trapper Keeper at the beginning of fifth grade. Now, my dad has always been a bit tight with the cash, and he didn't want to get me one because my sister had one that was in good shape that he thought I should use instead. The only problem with it was that it had a picture of a UNICORN on it. And my dad saw no problem with me taking it to school. Ugh. Luckily, my mom stepped up to bat for me and that's one of the extremely rare times I ever saw them get into an argument. But mom won, and I started fifth grade with an awesome new Garfield Trapper Keeper...
