Linux Media Center Edition is a free open source operating system 
designed to allow a computer to act as a Home Media Center and Home 
Automation Center.

It allows you to record and replay all your TV & Media/Entertainment 
content via easy-to-use GUI on a PC.

Watch this amazing demo video:
http://video.google.com/videoplay?docid=2176025602905109829&q=linuxmce&total=4&start=0&num=10&so=0&type=search&plindex=1

The "Follow Me" function will follow you through the house while you 
move and automatically controls all existing media devices, like TVs, 
Stereos, etc.

The Home Automation (or Smart Home) module lets you control lighting, 
climate, security, camera surveillance and alarms from the same display 
screen.

Of course, it can also handle VOIP (telephoning over the internet).

It is yours too. Get it from
http://www.linuxmce.com


See also:
General instructions to install the popular Ubuntu Linux on your PC
http://www.futuredesktop.org

Have a nice day,

Most kindly
  Moma