The application works within the phone's browser so doesn't require any new software. It does need to be open in the browser, though, to receive messages -- if the browser doesn't have the Google Talk window open, the user's status is set to "unavailable." Otherwise, though, the experience is meant to be close to that on a PC, with contact lists and conversation management.CNET News
Google Puts Instant Messaging on iPhone and iPod Touch
According to a Google engineer's blog post, Google has made it possible to use its Google Talk instant-messaging application on the iPhone and iPod Touch."In addition to sending your friends Gmail messages from your iPhone, you can now chat with them while you're on the move, too!" wrote Adam Connors of Google's mobile team.