If you actually plan on commuting aboard a Steamroller, think twice. The frame has no provision to mount fenders or a rack -- so prepare yourself for getting extra dirty and for carrying a courier's bag. What's more, if you use a reasonable tire (700c x 28 for example), there is unlikely to be room to mount a clip-on front fender. To me, these issues remain disappointing after having owned a Steamroller for several years. Unfortunately, the shop that built up the frame for me never mentioned this aspect beforehand and simply handed me the fenders from the old bike.

A surprising number of manufacturers now offer complete fixed gear models. For commuting, it might pay to start your search with the Redline 9-2-5, which has a steel frame and fenders. Specialized has a number of fixed-gear models that can accept fenders, but the frame is aluminum and will ride more harshly.

Finally, remember that commuting aboard a fixed gear bike makes the possibility of a flat tire even more odious than just using the bike for training or fun riding. You'll need a pair of box wrenches as a minimum for the rear wheel and something to center the wheel when reinstalling. The chain might need to be broken as well. You want the most "flat-proof" tires you can find. (I settled on Continental Contacts with good results so far.)