Web Comics

If procrastination was a martial art, I would be that Cuban taekwando guy who got banned for kicking the referee in the Olympics. One of the most efficacious ways of wasting truckloads of time is by reading web comics. Here are a few of my favourites:

xkcd - touted as a "webcomic of romance, sarcasm, math and language", it's reasonably nerdy at times and often quite dark.
Cyanide and Happiness - very crude, but also very funny. Pretty hit and miss though.
PhD. Comics - again pretty nerdy, and I don't know how relevant it is if you're smart enough to have chosen a profession that doesn't require you to do post-grad work, but it's pretty much always on the money.
Married to the Sea - very hit and miss. Often quite weird, and probably written by someone who's very stoned all the time.
Achewood - this is the very best webcomic out there. It's genius. It might take a bit of reading to work out what the hell is going on, but it's worth it. The good news is that Wikipedia can help (but Wikipedia always helps, really).

So yeah, wanna kill some time? Get on it.