LINUXs sucks
I agree use Mac OS X. I used to port linux and write device drivers, found lots of poor writen code. Linux has no control over its development. Anybody can hack into it. It has not gone to far on the UI side either. FreeBSD is better, try darwin with x windows on it, that is nice, ran it on intel before. Never used yellow dog. I used linux from 1992 - 2001 then switched to Mac OS X.
Solaris is very nice too. But that will not run on you iBook. I have heard lots of really good things about yellow dog.
If the linux community of dividing up work, quality control, and not try to have it run on every thing, like toasters, ipods, etc, maybe then they could develope a better system. I think freeBSD is more stable and has better internals. FreeBSD (darwin which is Mac OS X unix side) is a UNIX, linux is not unix, it unix like, but underneath it is its own beast.