PlayStation 2 enters online arena

The $40 adapter will plug into the back of the PS2 and allow the console to connect to the Internet via an existing dial-up or broadband account.

The network adapter officially went on sale Tuesday, although buying it may prove to be a challenge worthy of game heroine Lara Croft. Shopping sites for Wal-Mart and specialty retailer GameStop didn't list the product as of midday Tuesday, while Amazon, BestBuy, Buy.com and EBGames all listed the product as back-ordered, with some sites citing availability dates as late at Sept. 13. Sony said it would ship 100,000 network adapters at launch, with 250,000 on the market by the end of the year.

The company has set modest initial expectations for online gaming, with a handful of games supporting online play set to be available by the end of the year and no paid services on the horizon. But analysts and industry executives expect consoles to eventually bring online gaming to a mass audience, expanding the small but lucrative base of customers paying for online PC games.

While Sony is providing the hardware and software specifications to bring PS2 games online, it's leaving the details to games publishers, who are responsible for providing the infrastructure to make online gaming work.

By contrast, Microsoft is developing a closed system for Xbox Live, the upcoming online service for its Xbox console. Microsoft will take care of all network infrastructure and services for the paid service, with games publishers simply providing content to Microsoft. Public beta testing for Xbox Live began last week, with the service set to go live to the public on Nov. 15.

Nintendo has been the most cautious in its online plans. The company will release a broadband and dial-up Internet adapter for its GameCube console on Oct. 29, but support among games makers has been minimal, with Sega's "Phantasy Star Online" the only prominent online game planned for the console.