W*lm*rt has a cable lock with a Kevlar layer, it seems pretty good, that might take a good while-not be worth the trouble-to cut. I already have a couple of cable locks-one with built in lock, one with separate padlock. Where I live a cable lock helps, especially for a quick stop at a store, etc., I've never had a problem.

Haven't bought a U-Bolt yet but if/when I bike to work, I might try that also, the idea of keeping my bike outside for 9+ hours is something I'm not very keen with, but others who bike-customers and coworkers it seems have not had problems. I could check my bike on my breaks.