pureh@te, how would it be impossible? If you recode cowpatty to utilize CUDA, it could crack the hashes quite a bit faster. As it is, it would be impossible, but you could recode it to make it faster, right?
OP, as it stands, the answer to your question is no, if you wanted to attempt learning C for CUDA or Brook+(For ATI Stream) and recode the entire application to run on the GPU. (unless I'm missing something very drastic...)