i bought a pair of these from bt shop for £38.50 and have to say they work great imo.
one is upstairs near my modem and the other is plugged in downstairs in the living room as the wifi didnt reach there
* Data transfer rate (max): 200 Mbit/s
* Connectivity technology: Wired
* Host interface: Ethernet
* Interface: Ethernet
* Cabling technology: 10/100Base-T(X)