ZyXEL PLA-401 200Mbps Homeplug is a good little invention, it offers high speed network transfer speeds through you normal mains power. You may ask why you don't just use wireless, which is fair enough but if you want a connection somewhere that there is poor signal then the home plug is a sure way to have a stable uninterrupted connection and the speeds can be a lot quicker than wireless. In my opinion the Zyxel is one of the best models available, I have mine a few months now and it is easy to setup with the simple instructions, within a few minutes you can be up and running. So far I have had no problems at all and would definitely recommend this to anyone who is looking to get one of these.
If you want reliable connections then go for this product, it may be a bit pricey but I would advise getting this rather than a cheaper version.
Bought 2 of these (so 4 plugs) in an attempt to rid myself of wi-fi as far as possible and get proper media streaming working around the house. I have always toyed with the idea of a proper LAN network, and thought i`d give these a go as an easier, no cable option. The packaging advertises "plug and play" functionality, although I found this wasn`t quite the case. Having attached one to my router (netgear) and one to my PC (running vista home premium 32bit) I only got "limited connectivity" because the pc was trying to assign the same ip address to the plug it was attached to as it was the router ip. Easily fixed, although I am fairly PC literate. After that it was plain sailing, PC, XBox 360/PS3 and satellite receiver connected to a separate plug (via switch) and works like a dream. Stream HD content without any glitches and performs faultlessly. Manual not great and encryption functionality seems a bit hard to set up (although why you`d need to encrypt a network contained within your own house defeats me). All in all very impressed and would recommend to anyone.