I just put my application online and I've done it with this dev toolkit. it's almost ready for prime time. Let me know what you think and things you would add to it.
The application is called chatbook, you can add it from http://apps.facebook.com/bocazas/
It will allow you to chat live with people watching your profile as well as with everybody in your network.
I'm trying to find out a way to add a chat box in the profile window so you don't need to click the application link to chat with this person. So far I haven't found a way to do so, any ideas?
Hope you like it. Let me know.