Already working on that ;) I have a working prototype of a "bitcoin" client that replaces the hash generating function with completing a workunit of a BOINC project (the various @home stuff). It required some modification to the bitcoin protocol as the two tasks are not exactly analogous, and there are some different security implications.

Watch for it on HN soon...

It seems a shame that all the effort that people put into making padlocks is being wasted, what good does that really do?

Answer: padlocks, like bitcoin hashes, are a way of allowing people to collaborate without having to trust each other.

The rate of padlock production doesn't stay approximately the same when people double the amount of resources they put towards producing padlocks.

But the security of the bitcoin network also increases as the amount of computer resources put into mining increases.

> It seems a shame that all the effort that people put into making padlocks is being wasted, what good does that really do?

Sure, but if you could make it so a byproduct of the padlock manufacturing process was ice cream, wouldn't that be worth doing?

The time and energy used to mine is what provides the security of bitcoins and transactions. I would not call it a waste; it is what enables bitcoin to exist as a currency.

Another way to think about it is to imagine that each of these GPU rigs is like a branch office of the Fed. (yes, I'm kind of joking here)