Instead of a $99 custom button, what about a sub-$99 Android tablet? You can put them anywhere you'd put the button, and leave your home control app running with the screen set to never turn off. Turning on/off a light with a touch will then be no more effort than flicking a light switch -- there's nothing to take out of your pocket, no waiting for an app to open. This is how my home works. I built the app that runs…
I found some fat picture frames at Walmart that attach them to the wall perfectly. Mine have front facing cameras so I used motion sensing to fade them in as you approach them. Its creepy-cool in a good way. Sadly, they don't fade smoothly all the way in from black like an iPad. I'm hoping to upgrade later to jailbroken ipads.