I have successfully done it! I have a G3 300MHz CPU in my AIO running at 400MHz!!! The cache is running at 200Mhz and the system bus is running at 66.7MHz.
before I achieved this, I accidently clocked it to 417MHz on an 83.3MHz FSB. and the L2 cache was even running at 275MHz! However, the thing crashed shortly after. But now it is clocked back down to 400. Sadly, the cache will not go higher than 200MHz at this setting.
On a side note, my AIO now plays DVD's using VideoLan client in OS X 10.3 All this on an AIO Running at 400MHz and having only 2MB VRAM! The DVD's run flawlessely even when dong software de-interlace. The first thing I had playing on it, was Red vs. Blue DVD 3. In fact, it is still going right now.
I have achieved ultimate Geekdom!