I like the idea of Bitcoin, with one exception... that the resources could be used for grater good, instead of wasting them. How about making "valuable" calculations, instead of calculations, for calculations sake?
What I am talking about is modifying the BOINC client (
http://boinc.berkeley.edu/) and getting Bitcoins for generated work on finding a cure for cancer or some other project.
The calculations are not wasted, they are an investment into the cryptographic strength of the system. If people were willing to donate clock cycles to some other endeavor, they would do so. For a great many; however, the thought of helping to defend an online currency system, for which each is personally invested, is a far reaching act of service.