DistccPPCKnoppix is a Knoppix distribution (bootable Linux CD) which contains a working distcc cross-compiler for OS X. What this means is that you should be able to use it on any x86 computer, and get a machine that can be used to speed up your Xcode builds using the distributed compilation feature. I don’t have a spare x86 machine so I haven’t tried it, but it looks very cool.

http://www.csh.rit.edu/~benjamin/programs/distccppc.html