Having a second lock (not cable) is a good idea, after having wheels nicked once I like to lock both wheels as well as the frame. Losing one or both wheels costs a lot to replace. Lots of thefts are by opportunists who won't be lugging power tools around, they can easily nick unlocked wheels and components or cut cable locks with cheap portable tools. A couple of locks and a disc-alarm may make a pro-thief move on to an easier target. Ball bearings in allen bolts also works well, use magnetic or glue-gun to get them out easily or superglue for best security. I'd only leave a porn worthy/new bike locked up in public for a few minutes or within sight, use a beater/inexpensive/unfashionable bike for pub or work (unless you have insurance or deep wallet).
Having a second lock (not cable) is a good idea, after having wheels nicked once I like to lock both wheels as well as the frame. Losing one or both wheels costs a lot to replace. Lots of thefts are by opportunists who won't be lugging power tools around, they can easily nick unlocked wheels and components or cut cable locks with cheap portable tools. A couple of locks and a disc-alarm may make a pro-thief move on to an easier target. Ball bearings in allen bolts also works well, use magnetic or glue-gun to get them out easily or superglue for best security. I'd only leave a porn worthy/new bike locked up in public for a few minutes or within sight, use a beater/inexpensive/unfashionable bike for pub or work (unless you have insurance or deep wallet).
http://www.mechbgon.com/lock/index.html