yeah thats pretty much what happened, jaimie got them to associate the color orange or yellow or something with food. then a few days later he set up an obsticle course made of pieces of glass with holes in them lined with orange and the goldfish went right through.
I have fish that I sold to my LFS some up and greet me... it sounds absurd but they don't go to anyone else. Plus my brevis don't get scared around me, but dart in shells when anyone else is around.