There is a cross-compiling howto located at:

http://www.macbsd.com/macbsd/howto/cc-HOWTO

It is for compiling to the mac68k platform, but it shouldn't be too hard 
to adapt this to whatever architecture you actually have, I think.

Hope this helps.

Later.

-- 
Colin Wood                                      ender@is.rice.edu
Consultant                                        Rice University
Information Technology Services                       Houston, TX