I haven't really done any research about lighting controls. Am I correct that we don't need to put in extra wires to implement lighting controls since some products use power lines as the physical transport?
I hope that was what you were looking for. The powerline (non-hard wired) versions involve replacing swithces/outlets and then some plug in devices for control or signal boosting or the like.
I replaced my switches with Insteon devices and added a few control lincs to control them (and of course the devices to link to the elk).
The 'real' ones require a neutral wire however.
Note that for insteon for example (which I have), this can require some rewiring for 3-way circuits as they do not use travellers. The bright side is you can wire a switch with no connection to another switch and have them act as if they had a traveller (without ripping walls open).