i commute to work in union square and lock my bike up all day at one of those nifty bike shelters the city has been putting up (nyc has been doing some great stuff for cyclists the past few years-- more bike paths, more bike stands, removing some of those big bump things on the manhattan bridge, etc.). i use two u-locks and a mini krypto cable. rear u-lock + cable locks my saddle, wheel, and frame to the bike stand. second u-lock locks front wheel and frame to the stand. haven't had any problems with this setup yet. i don't lock my bike outside overnight, ever.