Lock Up Your Bike

This is from last year, but it's still a great video worth watching (similar videos can be seen here and here).

It's good to know these things, but it's also sad to realize how easily someone can take something that doesn't belong to them. Ultimately, bike locking is a question of deterrence. Any lock can be cut with enough time and effort, but a rational thief is going to target the easiest bikes to steal. Using a good locking technique doesn't mean a bike can't be stolen - it just reduces the probability it will be the one that gets taken.

What we really need is a lo-jack type system for bikes.