Here’s a fun new Facebook game app that just went live: The Mplayit Mobile Arcade, where you can play dozens of free mobile phone game demos, including top titles like Spore Origins and Guitar Hero Mobile. It’s a Facebook version of the Mpowerplayer web site, so it’s also integrated into the social network’s unique functionality. For example, you can share Mplayit game links with people on your friends’ list; when you click “Recommend” on a specific game, it shows up in your newsfeed. From the game publishers’ point of view, it’s a clever way of virally promoting and selling games on a network with 130 million users, many of whom might never even have considered buying a phone game otherwise. (The Facebook widget has a Buy This Game button which clicks you through to the title’s official web site.) For Mpowerplayer, it’s a new revenue stream: The company gets referral fees from the publishers featured in their application. As advertising budgets shrink to suit recessionary times, and developers are forced to get even smarter with their promotional dollars, I suspect we’ll see more Facebook applications like this one.