I also learned (the hard way) that if you use the embedded database (vice an external one) for Openfire, you'll run into issues with configuring the Asterisk-IM plugin.
I'm having a bit of fun with Openfire (the server) and Spark (the IM client). The Asterisk-IM plugin announces inbound calls with pop-up windows using Spark. Openfire also has a gateway function for just about every IM available. This allows you to see when your friends are online (or chat with them), even in IRC, without having to start up a dedicated client for whatever individual service they might be using.