This is the type of lock I use on my bike. It is always attached to the bike and has an alarm built in should anyone try cutting the wire.



Alarm Lock Site.
http://www.lockalarm.com/

I got mine from ebay, you can pick one up pretty cheap.

I spent a lot of money on my bike and the last thing I want is some bugger nicking it.



Here you can see the cable looped through my front spokes and around my fence. I also just bought a motion alarm padlock that I put through the front disc brakes n' spokes - (hard to see in this pic).

Regards
Tom