[KannO]

  in a system when you generate currency from nothing, this 
  is true. But if you use currency as an actual IOUs, you 
  would need to generate value to generate currency, and 
  thus, if you were to hoard currency, you are providing 
  value to the economy for nothing in return, which is a 
  good thing.

If it were possible to credit processing power dedicated to systems like folding@home or BOINC than I imagine that would be an ideal cryptocoin contender.

[jazzyb]

Such a thing exists: https://www.curecoin.net/

Edit: Also: http://www.gridcoin.us/