HTC has filed a patent for an innovative dual-slider design. Rather than having two slide-out keyboards (one text and one numeric), you would only have one with a portion of the QWERTY keyboard also used as a numeric keyboard in a different orientation. When the phone is closed, only the numeric keypad portion of the keyboard would show below the screen. Flip the phone to landscape orientation and slide the keyboard out and the full QWERTY keyboard would be revealed.
Curious to see what it could look like in real life? If so, check out the Photoshop renderings over at Unwired View.
So far, there is no evidence that HTC is planning to use the patent in a future phone. Hopefully that changes soon!