I would suggest reading up on the wiki, but....
Basically, any room with a media director can be controlled by a variety of orbiters and remotes.
do a search on the wiki for Orbiter.. it is an intelligent touch panel remote which is made out of commodity hardware.. I run one on a Nokia 770, and I have it installed on my laptop. I also run an orbiter on the Cisco 7970 phone.
These orbiters can move from room to room, and control every aspect of the house.
In addition, you also have support for Windows MCE style remotes, Gyration airmice, and Fiire remotes, as remotes.