All great advice. Got to the local bike shop, kick some tires, sit on a few, talk to the sales people, etc. I 'm lucky in that there are a couple smaller, very friendly and professional bike shops in the area that don't mind spending time talking to customers. In the end, you may find that spending a few more $$ at the lbs is a cheap way to get the right bike, and the right fit, up front... My .02

Oh, and although single-speeds are cool, you WILL regret it unless you're already in great cardio shape. I'm not even going to go "there" with fixies--they're trouble unless you're superb on the pedals....