Small idea for those who have their own wifi access point (and who hasn't nowadays, my laptop currently "sees" 4 beside our own): Some access points allow you to reduce the power level with which the antenna sends. In our 4-room apartment I've set the power to 12% and it still gives me 100% reception in the room furthest away from the station. Finding the lowest level that still works fine took some tries (and station restarts for each try), but I only had to do that once.
What did we gain? We save energy, maybe allow the access point to run a little bit cooler, reduce electrosmog, and reduce interference for other wifi owners in the neighborhood. There is just no reason why I should emit radio rays as far as neighboring buildings any more than necessary, since nobody there has any business in my network anyway, and if channels overlap only bad things will happen.