[jragosta]

Awesome screen saver.

My suggestions for freshwater fish (sorry if some of these are listed already):

Mickey Mouse platies
Turquoise gouramis
Red Fire gouramis
Rosy Barb
Harlequin Rasbora
Fancy guppies
Hatchetfish
Cardinal Tetras
Bleeding Heart Tetras

And how about a module where a piranha comes in once per hour and clears out the tank? :-)