Of course, I cheated. The trick is actually by using Google's own iPhone web application, which is pure HTML and JavaScript. Despite the name Google Talk, unfortunately it has no support for voice chat, rather only text chat.
The secret is to find the actual URL and load it in QWebView. Since initially it presents a login page, this particular client also automatically fills the username and password for you, getting them from its own login page. Overall, the code is very simple and does not even reach 200 lines, including some rudimentary error handling (wrong password, failed login). The user interface was created completely using Qt Designer. Careful readers might notice that I deliberately added the flick support (kinetic scrolling) using Flick Charm. This quick-and-dirty chat client was completed in less than quarter an hour.
Check the code at the usual Graphics Dojo git repository, find it under the webgtalk folder. This example requires Qt 4.5, which has just been released, in particular due to the use document.getElementByid. Exercise for the reader: tweak the little JavaScript snippets used in this program so that it works also with Qt 4.4. Another challenge: there is also
chat client for iGoogle which performs better but then it requires Flash plugin.
