Here's a snippet from a paper I'm writing on Reputation Capital and Exchange Mechanisms.
A reputation exchange is similar to a currency exchange, but trades in reputation capital instead of money. No one can force you to start using a new currency but if all your friends - and you - move to France, you'll want to start using francs. The Reputation Management Framework provides a plug-in architecture for Reputation Calculation Engines that make this sort of "reputation-exchange" feasible. The rules governing the "exchange rate" are set by the administrators of the respective systems - poor exchange rates will discourage newcomers while inflated exchange rates will disgruntle the existing community. A particularly compelling feature is that reputation exchanges - unlike their currency-backed counterparts - are not zero-sum, in that the process of converting a reputation does not destroy the old one - it merely enables some reputation carry-though systems.