Gresham,
Well - since this thread has gone in like 20 different directions anyway, I wanted to mention my observations regarding that "oriental goldfish" video you mentioned. I watched that thing longer than I probably should have, and talked to a lot of people - the only two ideas I heard were "magnets in the fish's belly" and the fish actually being trained to do this - neither of these allowed for my personal belief system to accept them.
It is evident from their fin movement that they are not actually swimming, so that eliminates the idea that the fish actually did that. The is absolutely no sign that any of the fish are struggling - like they would if magnets were dragging them around the tank (plus ending up getting dragged backwards, etc.)
If you watch, there are actually only two fish in two different poses. Their fins movements are as if the fish were just sculling, holding their position in the water. In my opinion, the videographer has just blue screened them in...
Jay