Follow Me

Follow-Me settings are just like a mini ring group, but it's tied directly to your extension. It's configured exactly the
same way as a ring group, including the ability to use an announcement to alert people that they're being transferred elsewhere.

There's a write up on using ringgroups for this at http://voipspeak.net/index.php?option=com_content&task=view&id=72&Itemid=28