This little contraption is called the iTwinge. The iTwinge attempts to bring a physical keyboard to the iPhone. Many iPhone users think this is not needed, but new iPhone users might think it's a great idea.
When this device was first making the rounds around the net it got a fairly chilly response. This video was then released to show everyone how it works.
It looks like a good concept, but in practice we're not sure. It looks a little bulky to carry around. I suppose if you dumped it in your bag and only pulled it out when you wanted to do a lot of emails that might work, but that seems like a hassle. We'll see what kind of success the iTwinge has.