I had one of these a while back (this one). I used it all the time with my mobile phone and it was both a great conversation piece and ergonomically and functionally superior to putting the mobile to my head.
Be ware, there are lots of people out there now manufacturing similar things and the quality varies dramatically. The one linked in PP looks to be of pretty poor quality.
The phobile is no longer available as far as I know which is a shame.