The thing that bugs me about the powerline technologies is that it doesn't necessarily do you many favours if you have to sacrifice a power socket to plug them in. I know a lot work over multi-socket adapters, but the manufacturers frequently say that that isn't supported (understandably, I guess). These devices'd make much more sense to me if they featured mains pass-through, i.e. plug them into a wall socket and then plug other stuff into a passthrough socket on the device. After a quick shufti on Amazon, something like
THIS.