I can control my lights in my home theater with my iphone. Z-Wave wall switches, a USB Z-Wave adapter and software is all you need.
Here The $159.99 combo is what I have but it looks like the program got about $80 more expensive since I got it last year. Light switches are about $30-40 per piece for HomePro ACT ones. I've got a few extras that I've upgraded to nicer models if you wanna buy them. They're still under warranty for another 2.5 years or so.