I assume at least someone here is using some kind of Linux distributioin on their Mac? What kind of experience you've had? I recently booted Lubuntu from CD (not installed on HD) on my 1.2GHz iBook and the user interface performance seemed to be OK and webpages loaded OK also. One thing which wasn't so great was YouTube performance, of course it is horrible with these machine anyways but with Lubuntu it was even worse. Probably the GPU acceleration is simply not on same level as with OS X? Lubuntu seemed to tax the system more since even after some use with Mac OS X the fan has not really been active, but with Lubuntu it didn't take that long. Volume -buttons didn't work. I was of course running live system so maybe after installing there would have been some drivers, fixes etc. which would improve performance. I wasn't surfing with the built in wifi because it for example needs separate firmware to work.