So, it is possible to run OSX on N900 (see http://talk.maemo.org/showthread.php?t=42908).
Would it be possible to install VirtualPC in this, and then install XP in that? I know it would probably take over a day to boot and stuff. But performance issues aside, is this possible?

Wouldn't you be better off trying to run it in bochs rather than trying to run emulated x86 on emulated ppc on arm? I'd be surprised if it booted in under a week.

I found this link, which seemed to explain things a bit:
http://lmgtfy.com/?q=xp+on+n900

It led me to this video which confirmed my suspicion that it is possible using bochs.
http://www.youtube.com/watch?v=zi9Di8bACpU
(note the "left to boot overnight" caption at the end of the video).

http://bochs.sourceforge.net/doc/doc...est-winxp.html