I use my computer for:
1. Surfing.
2. Downloading stuff.
3. Sometimes, like today, changing dead PSU (Yeah, sticking your arms and head in your computer once in awhile is certainly not uninteresting).
4. When there is time and energy, playing with kernel mode code.
5. Periodically playing artist in 2D, 3D, 10D, 11D, 26D....
7. Curse Flash, h.264 (see 3), and the holes in my socks. Ok, not the latter.
8. And finally using it to acquire expertise in HW for next PC (laptop, media PC) which never happens...
-edit-
9. Blame it for missed classic movies on TV. (Batman 2 is on, and the penguin is pissed)