i had to cut the u-lock off my friend's bike when he broke the key off of it. My dad had a pair of really old bolt cutters (think 3 foot long pliers), and that did the job quite nicely. The newer bolt cutters are much smaller when considering their effiectiveness, and are available at harbor freight for about $20-40...although im not sure how that compares to the price with a new nyc lock, last i saw for them was $100