Can anyone recommend a good bike mount for the iPhone 4? There seem to be a lot of reviews for the old models. Update: I'm mounting this on a Trek 1.5 Triple with [Bontrager SSR VR bars](http://bontrager.com/model/09170). Update: I've heard horror stories about phones popping out of mounts so having it secure would be good, waterproofing is a plus as well.