VIrtual Pet Monkey
Go ahead and laugh at me, I'm used to it! But I absolutely love my virtual pet monkey on my iGoogle homepage. All my life I've wanted a chimp (hasn't everyone?) and now I "have" one. If you have iGoogle, just go to "add stuff" then search for virtual pet in the search field. They have pandas, tigers, and a few others. I am genuinely getting pleasure out of playing with my monkey, and it is a stress reliever during a busy day at work or at home.
If you don't already have iGoogle, you really need it! There's another post about it you can read. Go to "search" on your sidebar.