Once a month (if I can find the time...which I usually do), I go to the Blood Centers of the Pacific (San Mateo) and make an apheresis donation. Spent my free time while on the chair watching Good Night, and Good Luck. The only downside is that you can't lift weights for a day, so my workout was a quick one today.
Wanna help out others (and watch a movie or surf the web while doing so)? Give apheresis a shot!