Control4 is a suite of home automation devices that can tap into your security system, lights, home entertainment, thermostat and various other electronics. Now they have an iPad app. And soon you will be fat.
This is only logical. The iPad, unlike the iPhone or iPod touch, is more of a shared device among your family. Having the Control4 app on there means everyone can use it, and it's more conspicuous on a couch or a table. Or you can bogart the iPad and feel like some sort of evil household dictator, flipping the lights off while your wife is trying to take a shower, but from the living room, so you have plausible deniability.
If this Control4 scheme seems interesting to you, keep in mind that Control4 is more of a installer-type system, meaning it's not so much a buy it and DIY deal. The app is free. [iTunes]