A just-launched payment service would allow users to make purchases for virtual goods via their mobile phone, rather than by credit card or online payment service. Boku follows a model familiar to many mobile-phone users: an approved charge appearing on one's mobile bill.

Forget your late-'90s memories of Beenz and such; the pay-by-mobile model is already quite popular in Asia, and virtual goods -- an $8 billion annual market, according to Boku -- are a good fit.

A YouTube video shows the process in action. On a Boku-ready site, you'd find whatever it is you need to buy and choose the Boku payment option. The system asks for your mobile provider and your phone number, both of which you presumably know, and sends a confirmation to your mobile, which you'll need to have handy. Responding to the confirmation triggers the transaction, and the charge appears on your monthly bill in the usual Premium SMS fashion.

Such a service could be catnip not only for the under-18 crowd (which, in theory, does not have credit cards) but for shoppers in other countries. To that end, Boku says it has inked deals with 170 mobile carriers in 50 countries, potentially reaching 1.6 billion potential shoppers. US Boku-friendly carriers include Alltel, AT&T, Cellular One, Sprint Nextel (including Boost), T-Mobile, US Cellular, Verizon, and Virgin. And Boku says also that more people have mobile phones than have bank accounts -- 4 billion to 2 billion -- making a mobile account the closest thing billions of people have to a credit line.

Among the games and applications currently accepting Boku payments are Aeria Games, Puzzle Pirates, Premium Football, and Facebook's Texas Hold'Em Poker and (fluff) Friends -- and Mafia Wars, that ubiquitous menace to productivity.

In addition, Boku announced Monday that it has acquired two smaller mobile-payment firms (Paymo and Mobillcash) and raised $13 million in venture capital. CEO and co-founder Mark Britto, pronouncing himself "thrilled" to be unveiling his system after five months of stealth mode, said of the business-side developments, "The strength of these two acquisitions and our recent financing will help us strategically to enable global consumer adoption and accelerate global carrier coverage."