Fixed wheel mania is rampant in NY at the minute. The influx has a lot to do with Republic Bike a company that enables you to build your own bike for peanuts in whatever color you like… when Urban Outfitters started stocking them all the Indie kids bought into the trend and now the city is full of multicolored bikes. Williamsburg is teeming with them. I went to an outdoor gig by the river a couple of weeks ago and there was a whole rail, about 200 yards long and 10 feet high that was covered in fixed wheel bikes that people had chained up all over it. I never got a pic sadly, as I was drunk and not thinking clearly, but it was pretty cool. In London the best place to buy fixies is 14 Bike Co in the Truman Brewery, which does the below… good wheels.