distributed computing

I'm in the planning phase of a demo which should demonstrate the power
of a distributed object technology which I'm working with.  Any ideas
for neat crypto-related distributed computation demos would be much
appreciated.

I've thought of:

* brute forcing RC5 (lots of people are doing this already)
* factoring attack on RSA modulus
* Certicom's ECC challenge

But I'm looking for something with more of a sort of gut-level appeal.
Cracking SSL packets might be good.  Hrmm.

thanks for any input ...

*jon