We're always looking for ways to help users engage with their friends and bring them into your application experiences. Today, we're excited to launch the ability for you to let users initiate Facebook Chat conversations in applications on Facebook. Not only will this allow for greater interaction within your application, but it can also provide significant growth as users invite their friends to join them in real-time.
With the new fb:chat-invite FBML tag, you can display a list of a user's online friends and allow the user to invite a friend to chat. Like with the multi-friend selector, you can customize which friends should or shouldn't appear in this list using the exclude_ids parameter.
There are countless ways applications can integrate this feature. For instance, users can invite friends to start a live game, a couple can plan a trip or their wedding together sharing links, or friends can exchange reviews on music/restaurants/gadgets--all without leaving your application. We're sure you'll come up with even more ways to use this new functionality.
If your application uses Flash or has content rendered by fb:iframe, you can use this tag wrapped in some FBJS code. For the technical details, read fb:chat-invite.
We'll have an XFBML/iframe version of this tag available soon.
As always, we look forward to your feedback on this feature. Please share your comments in the Developer Forum.