At the bottom of the post below, I more or less promised to shoot a series of videos about converting your bike to a single speed. I really wasn't happy about the quality of video I was putting up though (shot in hi-definition, I was converting the file a million times to get it uploaded onto youtube). I was also getting impatient and wanted to finish the job, so the series has had to be postponed.
You can click on any of these photos to go over to Flickr and see bigger images. It's amazing how much cleaner bikes look when you take more and more parts off them.
The drivetrain (44 x 16) involved a new bottom bracket, cranks that I got off a friend in a trade, spacers, cog and chain tensioner from a nashbar single speed kit, a chainring from the local bike shop, and single speed chainring bolts. I also put on new brakes, and if you look closely you'll notice a wheelset (mavic rim with deore hubs) that is probably worth more than this whole bike was when it was bought. You really can't beat good wheels though - upgrading wheels makes you suddenly feel like Hushovd.
And strangely, an immensely satisfying part of the conversion process is looking down at the bucket of junk that you took off your bike. If you put it all in a plastic bag and lift it up, you get a sense of how heavy all that crap was, and what a weight it was on your bike.