I'm not a programmer, so I wouldn't even know where to begin, but it is probably possible for somebody to create a nice app for the iPhone using either a) the newly released official SDK or b) the SDK for jailbroken iPhones thats been around for a while. I had my iPhone running one of the jailbroken firmware's for a while and there were a lot of very useful apps. I'm sure it could be done, but it would require somebody with some know-how to take it on.