How to focus when video-recording a self-portrait using rear-facing camera?

I'm trying to create a video of myself, but I'm having a problem: I can't get the camera on my iPhone 4 to focus on me. I'm using the rear-facing camera--to get the highest resolution image possible--rather than the front-facing camera. The problem is that every time I record, my face is blurry, and the background behind me is sharp. This happens when I do not tap to focus.

If I tap to focus on the center of the screen--while I'm behind the camera, before I sit, centered, in front of it--I still turn out blurry, because the camera stays focused on the background. I can't tap to focus on myself, because I can't reach the camera from where I'm sitting in the pose I want to be in.

Obviously, having another person operating the camera would solve this problem, but that is not feasible for me--I need to record myself, by myself. Also, if the camera had infinite focus, as I believe most cameras do, so that everything remains in focus, that would also solve the problem, but infinite focus doesn't seem to be an option on the iPhone 4--only auto-focus and tap-to-focus.

I also tried using an object as a stand-in for me. However, this didn't work either, because the object had different coloring and reflective properties than my skin, so the white balance was off, and also--for some unknown reason--the focus was off also. I suppose that if I had a life-size doll with fake skin that looked just like mine, that would probably solve the problem. However, I don't have a doll like this, so I'm stumped.

Any ideas?

Thanks.