A listserv that I belong to has a section that they call "the friday afternoon" thread - you know, time killers that are moderately informative or contemplative that help fill those final hours until the weekend.
I was reminded of that when I found bikefind's post under the bike as food thread to Scalzi's blog and the bacon on a cat photo. The ensuing blog entry and comments had me well amused for at least 30 minutes.
The paper airplane game used to be a good time sink too. I now have that on my smart phone, so it no longer has the same appeal.
Any other good time sinks that I should know of? Other than this board, of course.....