Bell EZ Guard Combination Cable Lock
Again, a cable lock won't get you very far in the city, but everywhere else, it's all you really need. Small town thieves will often take bikes because they're bored and it's convenient, so as a trip-up, a small and discreet cable lock will thwart these types of disinterested thefts. If this is all you feel like you need, then the $15 Bell combination cable lock will get the job done. Don't trust your $1,000 road bike with it, but for trips to the corner store, it affords you piece of mind.