[notahacker]

I doubt it would be that strange.

Presumably you'd control the value of currency through the same channels as under the existing system: indirectly by influencing interest rates, and instead of doing it by the Fed buying and selling bonds, you'd do it by imposing a new variable tax on leverage created by the banking system. It would be painful to adjust to (the base interest rate would be a direct cost rather than an opportunity cost, making banks' margins thinner) but ultimately work in a similar manner to the existing system.