Will Facebook users feel more comfortable trusting their credit card information with the company instead of social game developers and other payment providers when they go to buy virtual goods? If the answer is yes, we may see a new surge in revenue for developers, and for Facebook.

The question is closer than ever to being answered, too. Facebook is planning to more fully release its virtual currency, Credits, on third-party apps in the coming weeks. In the meantime, here’s a look at which games are already running Credits, and how they’re going about doing it.

Here are the games integrating Credits that have been announced so far, sorted by developer and noting the Daily Active Users (DAU) for each game:

• Crowdstar — Happy Aquarium (7.3 million DAU), Happy Pets (2.9 million DAU), Happy Island (just launched)
• Playfish — Restaurant City (4.2 million DAU)
• HitGrab — MouseHunt (173,000 DAU)
• Zynga — Pirates: Rule the Caribbean! (159,200 DAU)
• Playdom – (Lil) Green Patch (79,228 DAU) and TikiFarm (just launched)
• GPI – Robin Hood (11,104 DAU)
• Alamofire – PackRat (8,442 DAU) – although I couldn’t identify the integration point

There are two basic implementations seen to date:

1. Buying in-game currency with “Pay with Facebook” as an alternative payment method along with credit card, pay pal, mobile and offers
2. Buying in-game items directly with Facebook credits

Most of the developers opted for a simple implementation, just adding Facebook credits as another in a laundry list of purchase options for users:

Once users select Facebook Credits, they are presented with the option of using their existing credits if they have enough. Otherwise they are presented with options to buy with the credit card on file (if there is one), their mobile phone, or to select a new card.

Hat Tip The R. Hoov-diggity