The first CicLAvia is this Sunday! Don’t forget! The sudden Winter weather we’ve been having will have vanished by then, and it will be a lovely day. There’s a seven-mile route of city streets for you to walk, bike, run, etc. Should be fun!
See my description of one I saw in Morelia, Mexico, here. More information on this first LA one here and here. The whys and wherefores are here.
-cvj
Some Related Asymptotia Posts (not exhaustive):

Sounds great. There’s a move in this direction in some UK cities — it’s called Sky Ride.
–IP