The Pomeg glitch. (I bet someone has already posted this...)
Posted by: GoldenChaos
Date: 2006-07-12 21:31:56
Basically if you have enough HP EV's, and give your Pokemon a HP decreasing berry (the pomeg) while it has one HP left, then it's HP will go below zero and become an insanely high number.
This is all the info I could gather and if you guys haven't heard it (because I certiantly haven't) you might want to test it. It's supposedly for Emerald version BTW. It's probobly fake or been tested, but you can never be sure. Again, don't get mad at me, please!