OK guys, i finally got around to OCing this baby.
All went well, but i soon realised that u need to up the voltage once u go past the 600mhz zone.

I used stock cooling. AIR.
Should be able to push it even higher. But i decided to stop....for now.

Here are my results.



BTW. I have a GeCube, so it seems that all x1800XL are pretty standard.