http://www.mechbgon.com/lock
What kind of bike is it?
edit: I had asked about where you'll lock up, but your mention of the bike posts sort of answers that. Don't lock the bike to the circular part of it, since some of those can be broken by bike thieves using a piece of wood as a lever. Lock to the pole part of it. Better yet, if you can find two strong, permanently-anchored poles 1 meter apart, you can do the two-locks-on-two-poles method like the last photo on the page above. Make sure at least one lock is top-notch, such as a Kryptonite New York 3000 U-lock.