I thought I would share how I am using my iPad to control some of my lights and other electronics. I am really happy with how it is working out.
I am controlling my appliances with insteon modules on the hardware side and Indigo 4 on the software side of things. One of Indigo's features is a web server. The webpages it serves all update whenever there is change. That's what allows the iPad to interact with Indigo.
I am a Star Trek fan so I tried to make my first version look like trek padd. The top buttons activate macros that change several devices with one press. The middle section allows the devices to be controlled directly. The bottom section is misc. buttons. Below is a grab of how it looks now.
Any one else doing any sort of home automation with their iPad? What software and hardware are you using?