Virtual goods, that is, anything you buy online that has no material value in real life beyond the digital world, are one of the fastest growing markets in the Internet marketplace. Cellufun, the world’s largest mobile gaming community, is hoping to capture the quick cash of gamers around the world via mobile by giving them a way to buy virtual goods with ease.

The “FunCoin” currency, used for virtual goods transactions, is now available in over 25 countries to mobile phone gamers. Consumers can buy FunCoins to purchase Cellufun virtual goods and charge the purchase to their mobile phone bill.

For non gamers, the market might be hard to understand. Who would want to buy virtual goods that are worthless in real life? But that market, which has grown to $5.5 billion in three years, is destined for growth in the mobile space where gaming and entertainment is one of the top application uses beyond making calls. In the U.S., virtual goods transactions are predicted to top $1B by the end of 2009.

“We have no doubt that there is global consumer demand as well,” said Cellufun CEO Neil Edwards, in a statement. Cellufun recently launched mobile payments in over two dozen countries, which eliminated the obstacles that, they claim, have prevented virtual goods from taking off on mobile. Edwards notes that the company sold 2.5 million virtual goods within three months of launching them in the US.

Online apps are already pushing retail virtual goods. Zynga, which is the company behind popular Facebook games Mafia Wars, Farmville, Pet Society, and others, follow the model of being free to play, with virtual goods available for purchase.

Facebook is in on the online virtual-goods action, with their Facebook Credits currency that allow users to buy credits to use in multiple games on the social networking site. A new survey highlights that gamers are not only buying virtual goods online, they’re selling them too, making the virtual goods currency more legitimacy in the eyes of users, says VentureBeat. About 49 percent of social network gamers who have bought a virtual good have also sold one in the past year, with the median earnings equal to $50. With the rise of virtual goods online, it’s clear they have a place in mobile gaming.