SkyNet just got a little closer to reality…
Battlebricks, a site dedicated to "Battlebots"-type competition, only with robots constructed from Lego parts (their motto: "Where Bad Plastic Comes From"), has revealed a way to use an iPhone as the brains of one of their pint-sized killing machines, with a second iPhone (or a web browser) to control it.
In addition to the aforementioned hardware, you'll need to write some Java LeJOS Robot code, and some Google Web Toolkit web application code.
This YouTube video gives you a quick overview:
[Detailed construction directions at BattleBricks]