Washington St. through Walpole, Norwood, Westwood, Islington, and Dedham. South St. through Jamaica Plain. Over to the bike path on the Jamaica Way and into Cambridge via Brookline Ave (AKA Hospital row - hey if things get bad there's always a good trauma center nearby). Reverse to go home. I'll often add a little side detour on the way home if it's nice outside. I tend to limit the bike commuting to March through October because it's always dark outside (still ride on the weekends though).
Riding to work sure beats going to the gym. Being able to tear the legs off my riding buddies on the weekend because of the extra 200 miles a week is a nice fringe benefit!
I'd love to find a riding bud for the commute. If anyone rides (generally) my way, please contact me.