Tired of those cliched old fish swimming across your monitor? Then check out the Space Wars 3D Screen Saver for Mac OS X (there's one for Windows as well). The demo screensaver features a battle between squadrons of small fighters, but like the aforementioned virtual fish tank, those who register the screensaver can download additional ships. The overall effect is reminicent of a cross between the old Wing Commander games and Babylon 5, with lots of quick turns and explosions.