A lint roller or tape on your hands or one of the velvet lint removers (wipe one way and it collects lint, the other way releases it). I wait until I'm done, though. The cats always return.
Haven't you hear the saying, "Cat hair increases the insulation value of a quilt." ?
A bigger problem is that my kitty boy likes to shread batting, the polyester more so than the cotton batting, so I can't leave any batting out anywhere or sticking out of a quilt or it's gone.