Ooh, thanks UR, I haven't heard of the cheese type...I'm a cheese lover so that might be a new one to try. Tuna-mayo is a pretty common filling, however I have not tried it. The pork filling sounds delish as well--a fun dinner party appetiser idea.
I think those pickled plums are called umeboshi...and while I haven't tried them, I've seen them in jars at my Asian grocer. I'm thinking they're an acquired taste.
Bento is plastic and comes with space in the lid for a little fork and spoon. Very compact and cute...yeah, I'm a sucker for the cute-factor. Got it from ebay. There's a seller with a shop called The Bento Store who sells lots of bento box designs as well as accessories like weiner cutteres and onigiri molds.
It's my latest obsession...