hey alethiophile,
see the downloads from NiLuJe in the jailbreak thread
here. One of them (i think it's the last one, x-tc) contains a file called x-compile which is a log of his cross-compilation session including some small patches you have to apply to get the cross-compiler built.
fwiw, i built crosstool-ng 1.9.3 (NiLuJe used 1.9.0). I see now that 1.10 was released a few days ago.