Originally posted by Nubius
I've ripped off that 3rd grounding plug before because of not having a socket that had 3 prongs.
You use a plate-eye socket adapter. It's a two-prong plug with a little bent out third peice that has a hole in it. You remove the center screw from the outlet plate and screw the adapter to the outlet plate with the screw you removed. (This isn't really safe, but it could be worse...)
Anyway, here's some good grounding tips:
1. Just touch the case (or case frame if you have one of 'those' plastic cases).
2. Leave the plug in the wall if it's a circuit-breaker outlet, and just break the circuit with the little button on the outlet (not powerstrip).
3. Take the plug out of the wall and stick it in your pants (just don't walk off).
If you're not sure if it worked, rub your feet on the carpet a few dozen times, then touch the case. If you see lightning, you know the transfer of bad is working.