Although it's very tempting to build highly integrated hardware extensions for the very sexy devices that apple makes there is a better way to go about building specialty hardware.<p>Build for the wireless LAN.<p>Adding a webserver and wifi interface to even a modestly sized hardware device is cheap and getting cheaper. Open Protocols win in the long term.<p>Note that this means you should be able to reach most of the  app phones on the market, and not be stuck with Vendor A's weird policy bugs.