I'm pretty sure that's impossible the iPhone needs to sync with a computer. At least, before jailbreaking. If you jailbreak, I have no idea, as I'm a member of Team Pure! Haha.
Yea the easiest way to do that is to upload the pictures onto a computer, and either sync your phone with it or use drop-box to instantly have the photos on your device.
You can't sync directly between a camera and your iphone though.