You can buy micro screw extractors, which supposedly work well (haven't use one myself). Super glue might work, but I haven't had any luck with this before.
I find the best way to deal with stripped screws is to grind a slot into the head with a dremel tool, or just cut the head off and use pliers to turn and remove the thread. This depends on how flush the screw is with the casing however, since this will likely get damaged as well.