There is a great article about the fixed gear phenomenon in this month's FM Magazine. Excellent piece by Tuyet Nguyen, definitely one of the better ones I've read, and I'm not just saying that because I was interviewed for it. Honestly.
The rest of the mag is very good too, and it's free, so if you can get your hands on one, make sure you do so. Support those independent publications, especially when they're supporting us!