I'm a walker, love to walk. I get a kick out of seeing the faces of friends when I tell them I walk to stores accross town (about a 5 mile walk round trip) and tell them it takes me a little less than an hour (plus the time spend wandering the store) They think I'm crazy. LoL.. this from friends that take their car to go 3 blocks to a corner store for milk.
I also ride a bicycle (which I named Harley) which is a CCM 10 Speed. The bike actually broke a few years back, and I don't really miss it. I really prefer walking. I great day for me is when I make the trip into Montreal and spend the day walking around town. from about 6am till 11pm. Yes I cover alot of ground, but it's great, simply wonderful.
Spring is here, the boots are stored and my walking shoes are back in business, Oh the joy.
So my vote is Walk, Biking will only keep your legs in shape. Walking will keep you in shape. Also, By walking every day, you'll find that you'll see many of the same people, and you will fast feel like a member of the morning local crowd.
nuf said,.. Cheers!
P.S. Did I say I love to walk?