Virtual worlds and MMOGs are taking another step closer to meatspace — the real world — with the growth of in-game and cross-game economies.

Recently I read Julian Dibble’s book Play Money about “quitting his Play Moneyday job to trade virtual loot” as a gold farmer in the commercial metaverse — Ultima Online, World of Warcraft et al. Besides a good read, Play Money makes it abundantly clear that the virtual economy will be nearly identical to the real one and that it is growing apace with the explosion of new online realms.

That point was driven home when I was solicited by a startup seeking to build a cross-game currency exchange to facilitate trading the currency of one virtual word for that of another. Think WoW “gold” for Second Life “Lindens” or Whyvillian “clams” and you get the idea. But where Dibble had to skulk about to buy and sell his gold, in the model envisioned by this startup and others, like the recently organized PlaySpan, you’d use a secondary web service to buy, sell and trade between MMOGs and virtual worlds.

Bankinter in WhyvilleAnother take on the virtual economy came in a press release from Whyville.net about an in-world banking service sponsored by Bankinter. After only a week of operation, Whyville’s users have already elected to deposit more than 100,000,000 clams (Whyville’s virtual currency) into the virtual bank. 90,000,000 clams have been deposited in certificates of deposit (CDs), while 21,000,000 have been deposited in interest bearing savings accounts — totaling more than 25% of all the clams in circulation. Users visit the bank or use a virtual ATM to monitor and manage their accounts, and in the process learn how to use these basic financial instruments, providing valuable real-world lessons to all the hard-working Whyvillians.

Whether it’s cross-game trading or in-world banking, virtual economies are inevitable because they serve real world needs of players. And while it’s too soon to tell if publishers will cooperate or try to block these efforts, they signal a new level of verisimilitude offering opportunities for entrepreneurs and players, and for smart parents and teachers who can use these simulations to help kids understand real world economics. Who said video games weren’t good for you?