Hi, I like the rei light weight cable idea above. But I prefer a snowboard cable lock because the combination housing retracs the cable:
http://www.rei.com/product/793031 All in one simple unit. It is also multifunctional for travel. I would also keep the expense of my bike at the value point so if it gets stolen somewhere it won't break me. Simple, at the value price point. The ticket to most things.