@OP, do you have any suggestions that would actually help the crpytocurrency? it seems like your suggestion of forcing them to find two hashes would just halve the difficulty.
I'd like to see a coin with alternating blocks CPU/GPU.
why?
If you read the bit after that, you would find out it was merely an example. An example of thinking OUTSIDE of the box. People are too limited by what is already out there, re-using the same code, with minor changes. Namecoin while still just bitcoin, thought a
bit outside of the box, and made something useful, why do you think it has worth?