Welp, the title kind of says it all.  I'd like to see someone start up a service that allows for the exchange of game currencies across different games.  Not sure of the logistics or if there is even really a market for this.  

Essentially, you could acquire game currency in one game and somehow transfer currency in a certain proportion to another game.  The world does it with fiat currency so I figured life would be a bit easier for people that play multiple games if they could transfer some of their wealth over to a newer game or a game they spend less time on.  I'm not sure how this would affect game economics for the individual games or, if there were economic disruptions, what those impacts could be on actual gameplay.  i.e.  Less people farming could lead to less people to gank.  Less people at middle gear levels and more at beginning and end where they could just buy better gear.

Anyway, I was thinking someone could create their own digital currency, that would be for purchase in participating games.  That currency could then be used to purchase currency for other games or hey, maybe even legal tender currency out in the non-digital world.  This way you could start with an edge over other players on a new game release or spend more time on a game you love to play and transfer wealth to a game you like to play every now and then.  You could even join friends on a game that is new to you but that they've been playing a while and not have to start at 0 or be a bum and ask for currency.  

Like I said earlier, I'm not sure of all the implications or if the game developers would agree to such a thing.  Just thought it was a fun idea so I threw it out there.  Let me know what you all think!