For any who are interested, I've just finished writing my review of the available intercom systems on the market including the BlueAnt InterPhone. It's fairly long, as it also includes a pictoral "how-to" on making your own neckband for the InterPhone, since it was originally designed for motorcycles. It's located on our personal tandem blog:
Oh, and I suppose I should say that I am not employed by, paid by, nor have any interest whatsoever in this company. Just think they have a good product.