I bought 2 of these (the minimum, obviously) to plug my Xbox into the network router (Netgear). Straight away I got it working - no problem setting up; you get a couple of lengths of ethernet cable with them, which I wasn't expecting.
Anyway, it's a breeze and I'm getting another unit to replace my wireless network which spans my 3 storey house - and not very well at the minute. Plugging one of these units in has seen an instant speed increase, even though it's not on the same mains ring.
The other thing is that, unlike some units I'd seen, they're small enough to allow other adaptors, plugs etc to be plugged into the other socket in a twin arrangement.
Finally - I shopped around a bit for a good price - and this beats the other prices hands down for something that works very well indeed. So in all, it comes highly recommended.