Yep....just like Facebook!
http://m.ajarnforum.net
The beauty of it is that it's just a vanilla redirect that does nothing, but just allows me to give mobile users the impression I'm catering specifically for them with their own url....this plugin does the rest, and I avoid VBA.
On the other hand if people do go to the regular address, I've set up meta refresh in the mobile template's portal template. The disadvantage is that it does display it first before diverting.