The Google (Nasdaq: GOOG) Nexus One Android smartphone is now available for sale on the search giant's Website, but the unlocked version won't be able to support 3G data services on the largest GSM network in the U.S.

Google is now selling the unlocked Nexus One for $529. It won't, however, support high-speed packet data service (HSPDA) 3G over the AT&T Inc. (NYSE: T) network, only slower EDGE services. "Buy the phone without service and insert your own SIM card," Google says on the site about the unlocked phone. When you click through, however, the catch is revealed:

"The currently available Nexus One device is unlocked and will recognize SIM cards from any mobile service provider using the GSM standard, but is incompatible with the frequency band used by the AT&T and Rogers networks for 3G data," Google notes. [Rogers Communications Inc. (Toronto: RCI) is the largest cellphone provider in Canada.]

"The Nexus One's antenna supports four GSM radio frequencies (850/900/1800/1900) and three 3G bands (bands 1, 4, and 8). These cover most major GSM mobile providers worldwide; however, the 3G band used by AT&T and Rogers is not supported," the Website adds.

This basically prevents Nexus One users that want the fastest 3G GSM performance from using T-Mobile US Inc. . (See Open & Unlocked. So What?)

As expected, T-Mobile will sell the Nexus for $179 with a two-year contract. The ad also reveals, however, that Verizon Wireless in the U.S. and Vodafone Group plc (NYSE: VOD) in Europe will offer the phone in the Spring of 2010.

Google says that it is working on a CDMA version of the phone now.

"We are working hard to provide Nexus One phones optimized for the Verizon network -- please stay tuned," the firm notes. "The Nexus One for Verizon will not be a GSM device, so it will not be compatible with T-Mobile, AT&T, or other GSM networks." — Dan Jones, Site Editor, Unstrung