Facebook said there would be “100 or 200” payment options available for Credits, when it detailed plans for its virtual currency back in April. Now we’re seeing more of these options appear for users.

The latest, not announced, but visible on the Credits Facebook page, is the ability to exchange your unwanted gift cards for an equivalent amount of Credits (minus the processing fees). Facebook first mentioned its plans for the gift card exchange at f8, although it’s not clear when it went live.

Plastic Jungle provides the service — it already has a venture-funded business going, letting people cash in their unwanted gift cards and buy new gift cards at discounts. The rates for Facebook users is the same as otherwise available: “up to 92% of the balance” for converting the value of a gift card to Credits. Plastic Jungle has other deals with social application service providers,including Offerpal.

Among other new payment options for Credits, one announced this week is the ability to buy Credits using MOLPoints, a popular payment service in Southeast Asia. Facebook already provides direct credit card payments, Paypal, mobile payments through Zong, and offers. Expect to see many more show up soon. Because Credits come with a 30% cut for Facebook and other costs, some developers have so far been reluctant to make Credits a more prominent part of their applications. But the more ways there are to get money into Credits, according to Facebook’s plan, the more people will do so and then start spending this additional money with developers. This way, the costs of Credits will be more than compensated for, and developers will want to use the virtual currency as their main payment method.