I definitely have to agree with RwGast, you are a moron. While it's okay not to know anything about PPCs and to ask questions, it's very irritating to read 2 different topics asking the same thing. It's also irritating that, even though you obviously don't know anything about it, you ignore people who are telling you that it's not possible. Your PPC might be stable when you're playing around in the start menu BUT THAT'S BECAUSE IT DOESN'T NEED THE EXTRA POWER, THEN! As soon as you use an app that would benefit from the extra speed (Chopper Alley, Pocket Quake, SNES or Genesis emulators), your PPC will normally crash running at 236mhz, and will need to be reset and switched to 221mhz. It also drains the already limited battery life MUCH faster. Therefore, most of the time, it would be better to actually UNDERCLOCK it, to increase battery life. Anyway, give an actual reason why you need to overclock more, not just "..236mhz is too sloooow.."
If you're still stupid enough to want to try overclocking your PPC, send it over to me - i'll give it a try...(But i won't accept liability for damage that may occur...

) ..Or just put your clock forward 10 minutes.