This is a good idea for other languages.. also for other platforms. Awhile ago I had to do some cross-compiling for arm, and I think I created a nice set of retargetable packages for compiling cross-compiler packages. I should dig these out and get them into the general consciousness.
I keep meaning to eventually try the cross-compiled stuff on the old Intrinsyc cubes I used to use as dns/dhcp servers. At the time, I was cross-compiling for other purposes, but the cross-compiler worked great.