Have you used the Web MD Symptom Checker? It's the most vile creation.
Basically, you click on the virtual body and check your symptoms and then Web MD tells you when you're going to die (Hint: Tomorrow!) I think this would be a terrible thing to do if you were actually afflicted with something, but when you're perfectly healthy it's totally awesome. In a kind of sick way.
You can just go through and click on stuff and be like, "What would happen if I just couldn't blink anymore?" Then you read about some terrible disease, shudder, and click on another symptom.
I used to be kind of a hypochondriac (I have since gained complete disregard for my health), but I'm still fascinated with all kinds of creepy, gory, medical shit. This is one of the greatest ways to waste time. This, and Stardoll.