I downloaded a cross compiler that was made to make ppc elf binaries. I don't think there is an Apple supplied ppc elf cross compiler.
I'd suggest building your own binutils and gcc, it doesn't take too long and usually works a bit better.
(Unless others here think it's OK to depend on bash instead.)
Come on people, switch to bash. It's better. What would we miss if we did switch to bash?
I think there are probably quite a few people on tcsh or zsh. sh is virtually guaranteed, bash is not.