Casey, this is the most Casey thing I've ever heard, using an iPhone + some hackery when even cheap Amazon no-name PTZ cameras ($30-40 usually) natively support onvif! I'm happy it worked for you though.
-Casey
If anyone does not listen to ATP, I cannot recommend that show enough. I'll add that you do have to have at least a tolerance for certain of the 3 hosts' assumptions, namely that one should be an Apple user for life. Not that they go easy on Apple, but they seem to be dedicated lifers no matter how bad Apple gets.