Boston is a fucking awesome running city. Even in the winter. Just buy an iPod/iPhone nike + thing, or get a cheap GPS watch... the coolest guys at the gym are the ones who come in from roadwork [especially when its freezing outside] and then do weights. so manly and outdoorsy
I ran in Boston last July and not only had a good run, but was amazed at the number of people out for a run. I've run in many cities, but have never seen so many other people out running as I did in Boston.