[Jeff]

I was pleasantly surprised to find that they switched on the integration on my Gmail account yesterday.

You can see the "Quick Contacts" in the left hand column below the navigation menu, and a sample chat window in the lower right corner. It doesn't work if you're using an SSL connection (i.e. https://gmail.google.com), only the standard http:// site gives you the integrated chat functionality, at least for now.

The chat windows pop-up using AJAX within the browser window, but can be split out into their own browser window (and collapsed back in later, if you choose).

There's one thing I really don't like about this --- no notification! I typically run Gmail in Firefox, with about 10-12 tabs open. There's no notification of an incoming chat message, either visual or audible. Unless you're looking at your Gmail page, you might miss incoming messages. Other than that, it's pretty cool.