If it's not Scrypt / SHA256 stuff but something really innovative then why not.
However your USD will only be worth what people think it's worth, you can't just say my USDCoin := 1 USD
My hypothetical case is the US government creating an alt currency for the US dollar, and start issuing dollars through the netwofk @ 0.01 USD per block, as it would be less expensive for the government to issue new money this way than printing money on paper. I'm just exercising future possiblities for cryptocurrency uses.
Would you be interested on mining at a low reward as a penny per block if you are getting REAL dollars? (no asic allowed).