I've come across the method of using Stanley knife to slice off the leads - if all you want to do is remove the IC. Having tried it myself a couple of times, I've found the theory is ok, but you have to be very careful to avoid cutting into the board below, and the "wedging" action of the blade forcing the lead away from the IC body can lift the pads off the board. The jury is still out on that technique as far as I am concerned... A Dremmel sounds like a good idea though, I'd definitely give that a go.
Are you just looking for ways to remove an entire IC, or do you need to be able to isolate individual pins?