I may have been introduced to bento back in high school (aka, "the eighties"), but I know we used to eat it when I was at Ziff-Davis out in the Bay area in 1992 (with font-man and Colin). Mimi Ito apparently makes a lot of bento -- every day for her kids! And she's posted a lot of beautiful bento photos at flickr. There's a large set of images and a smaller tagged group, they may overlap, not sure.