Here’s another: they’re going for a browser-based Google Voice (like the rest of us are using). This option was formerly less viable, but now Google has improved the mobile version of their site for iPhone and Palm Pre users.
The controversy, of course, is that Google Voice allows users to make calls and now send text messages without charge, and without using the minutes in their carrier’s plan.
The New York Times documents the improvements:
Of course, iPhone users were always able to point their mobile Web browser to m.google.com/voice to access their Google Voice accounts. But plenty of things didn’t work right. For example, making calls was a two-step process and the outbound caller ID feature didn’t work, meaning that whoever received the call couldn’t see who was calling, which is one of the more compelling features of Google Voice. [Senior product manager for Google Voice Vincent] Paquet said that all those problems have been solved, and that the new version of Google Voice also offers free text messaging.
Naturally, Google maintains that this isn’t a strike against mobile carriers, just a response to the high demand they’ve had from mobile users with browsers capable of interpreting HTML5.