What is the device called that transmits broadband over power lines?

[StephenCampbell]

I'm moving into a room in a house that has a DSL modem on the opposite end from where I'll be, and I need that device that you plug into the wall that transmits the internet connection over power lines in the house. What is this device called and are some better than others?

Thanks

 

[HellDiverUK]

http://www.netgear.co.uk/wallplugged_ethernet_bridge_xe102.php

Don't bother with any others, that Netgear is brilliant.

The one I linked is the UK version, the US one will obviously have a different socket.