Ergonomic Mouses

Some new ergonomic mouses have been recently released and from the looks of it they seem quite innovative when it comes to design. They were built in mind to make using a mouse easier on the wrist and it is designed to be hold more like a pen then a traditional mouse. It basically conforms to the hand like a pen would and costs around $30. You can use it with Windows XP, Vista, or Windows 7 and it might be an interesting experience using it as it is very original. I wonder in what direction will the development of such products go. Are they going to replace our traditional mouse? Only time will tell.