I also use ccache for speeding builds (notice it's already in the
Gentoo Power Setup's initial make.conf):
the page: http://code.google.com/p/glibcsnap/downloads/detail?name=emwrap.sh&can=2&q=
has more info, but I usually don't get more into it than the Gentoo
Power Setup reminds me to do.
there is at least one other tool I was going to mention, but I
remembered it when i was beginning that last paragraph, but I can't
think of it now, I'll email it to you if I remember it.
Hope that helps,
James