Reason #4,204 why you need more computers at home..... distcc for distributed builds. Now built in nicely to gentoo's build system. There is a nice article on optimizing it and for while it's slashdotted here's the article text. I set this up on my two gentoo systems in about 2 minutes, emerge distcc and ccache, put "distcc ccache" in the FEATURES in /etc/make.conf, then run distcc-config --set-hosts "localhost ip.of.other.host" and you're done.