http://distcc.samba.org/ - network distributed
http://ccache.samba.org/ - cached compiling
For distcc to work, add -j4 to relevant $MAKE in toolchain.sh and start distccd everywhere. Then build like this:
I found both tools are in fink (unstable), cygwin and debian.CC="ccache gcc" PSP_CC="ccache distcc psp-gcc" ./toolchain.sh