If you've decided to rely on your iPhone entirely for snapping photos, you may as well go all out and add the accessories you need, like this 6x optical zoom lens.
It's attached to a clear case cover that's closed over the iPhone, with the lens covering the camera eye on the back of the phone. After it's attached, it works just like any other camera lens. At only $15, it might be worth picking one up!
Check out this other camera phone lens: