iPhly Radio Control For iPhone
A cool idea indeed. He has even gone as far as to develop the iPhly trainer cable that let you test the software portion along side your regular RC transmitter (that another pilot could control simultaneously) so you can get the hang of it without risking a plane crash.
Good luck Ari.
http://www.kickstarter.com/projects/ari-krupnik/iphly-radio-control-with-iphone/widget/video.html