Mini cups for dipping sauces
Bought for US$1.50 at Daiso in Daly City, CA (20 cups total). These are cool -- you put your thick dipping sauce in a little cup and cover it with the little plastic film covers. As long as the sauce is viscous and you don't treat the bento roughly in transit, it stays put. (Recommended for mayo, ketchup and tartar sauce.) Interesting. Blog entry here.