Just out in public beta, GameLayer’s Passively Multiplayer Online Game is a fantasy MMO that’s largely played from a web-based toolbar. But instead of exploring dungeons and killing monsters, as you would in an old-school MMO, there’s a genius twist: You gain points and achievements through browsing the web itself.

“PMOG is an asynchronous game that can be played on any web page,” explains Merci Hammon, chief creative officer of GameLayers, a startup backed by backed by O’Reilly AlphaTech Ventures LP and Internet guru/venture capitalist Joi Ito. “The game invites players to use the data they already generate online to fuel ongoing social play.” With Amazon turning its crowd-sourced advice site into an MMO, and social networks like Facebook already feeling somewhat like role-playing games, PMOG is merely the next logical step — that of turning the entire Internet into a game world.

So instead of finding treasure by exploring a dungeon, you earn PMOG achievements by visiting designated sites; a “VC” award for frequenting Techcrunch, for example; a “Bounce Bounce” award for regularly stopping by Boing Boing, and so on.

From a business standpoint, it shouldn’t be difficult to generate revenue from a game that rewards web activity. “We have a couple obvious options,” Hammon tells me, chief among them sponsored content. “Right now we just know we’re not going to blast ads at our players.” For the moment, then, they’re working on honing a system that turns web browsing from a mostly random activity into goal-directed fun. “A lot of the players in our closed beta have remarked how addicting PMOG is,” she notes, “and how it’s led them to sites unknown online.”