eSheep is just about the most awesome thing ever. I urge everyone to try it. It's a really small download and it gives hours of adorable entertainment. I've had mine fall flaming from the sky into a conveniently-placed bathtub as well as be abducted by aliens. There are also more normal things like eating flowers, rolling around, and falling asleep [awww...] Apparently, sheepy also falls in love, but that has yet to happen with my eSheep.
My friend Anita got me hooked on this and it's so cute. It just runs around your desktop as you do other things and, like I said before, it's just plain amusing. Yay! eSheep!