Don't ride a fixed in traffic!....Does anyone ride fixed with two brakes? What is that like? They get you fit though, I reckon a 10 mile ride is like doing around 20 on a geared bike!
Got a friend that went to 2 brakes on his fixie after being in 3 wrecks with cars in 2 months...yep they pulled in front or cut him off without looking. He said that he didn't like the way it looked but he could stop faster and it was safer...with less leg strain. I guess most of it depends on the traffic where you live.