Note from PCG: this site, http://www.fish-school.com, was gone for a while, but it is back now, better than ever. You MUST take a look at this!
"Believe it or not, it is easy and fun to teach your pet fish to swim through hoops and tunnels, do the limbo, eat from your hand - even play soccer! This is NOT a joke. You can do it yourself, using the new R2 Fish School Training Kit..."