1. ZGrip Pro for the iPhone.
2. Do-it-yourself Tripod mount
5. mini spring clamp
This is my home made solution. I went to my local camera shop, Peace Camera and purchased a mini spring clamp tripod mount that will hold my iPhone.
The clip will attach to my tripod for stable video recording.
They didn’t go into detail about how they made the iPhone 3Gs shoulder mount but if you pause it a couple of times I’m sure you can figure it out.