When I bought my first fixed gear bike, I rode it around my neighborhood (mildly hilly) and almost immediately put a front brake on until I learned to regulate speed by resisting, skip stops and skidding. Thats when I was running a 48x18 (2.7:1 ratio and 72 gear inches). 6 months later, running 49x16 (for a gear ratio of 3.1:1 and almost 83 gear inches) I decided to ride without a front brake on a hilly, city 7 mile ride. Downhill was fine at good speed since I wasnt spinning my legs off... but after climbing up and down 3 mild hills, my legs were jello. It's SO much easier on the thigh muscles using the front brake since you dont have to exert so much energy and strength to skid/skip and resist gravity LOL... but I tried for a long time to NOT use it and learn how to ride sans brakes. Around my city, Baltimore, we have hills. If I plan on riding more than 3 miles on my fixed gear bicycle, I will probably toss on the front brake.

I feel comfortable riding everywhere with no brakes now but if I want to ride fast, I prefer the front brake. If I'm just riding down to the local bar or inner harbor or will be riding on primarily flat surfaces (within a few miles), no brake is fine.