I asked a similar question on dirtyimpreza and got some good input. http://www.dirtyimpreza.com/forums/s...ad.php?t=10225
The general consensus is that you shouldn't do it if it can be avoided. This is more rallyx than autox, but they suggested pendulum turns and left foot braking as an alternative. Of course, if you have an sti, your center diff opens up when you pull it so you can do it all you want with no ill effects, at least for the center diff. If you do it a lot, you will burn through the shoes for your hand brake in no time.