One more thing: you need to know the difference between different types of frames. Stay away from racing frames-- you won't be able to commute comfortably on them. You will want either a sport touring frame, or a touring frame. There's a difference between the two. Basically, a racing frame has upright angles on the head and seat tubes, and a short wheelbase (less than 40"). A touring frame has less upright angles, and a long wheelbase (41-42 inches). A sport touring frame is in-between. A sport touring or a touring frame should have brazed-on fittings for attaching fenders, racks, and water bottles, all of which will be useful for commuting. Many people advertise their used sport touring bikes as "touring bikes," when in fact they're sport tourers. Even my Motobecane, which has "Grand Touring" silkscreened on the top tube, is a sport tourer. The difference is that a real touring bike will be more comfortable and more stable carrying 50 plus pounds of luggage long distances day after day, while a sport tourer can carry a moderate amount of luggage long distances, but will have more crisp handling.