Hinges. Not the most exciting of inventions, though where would we be without them. HTC have patented a new design of hinge, seemingly the sole purpose of which is to look nicer when closed. However, it might also make for a more book-like clamshell device, potentially with dual displays in the same manner as the Microsoft Courier.
Another benefit of the hinge design is that, when opened, the two halves of the device would be flush with each other. Current hinges would either leave one second proud of the other, or leave the barrel of the hinge protruding along the middle; the design would allow for the gadget to open 180-degrees and lie flat on a table.
That way, two touchscreens could feasibly nestle up so close to each other as to almost be a single panel, though obviously that would require some seriously skinny bezels at least near the hinge-join. HTC aren't giving away any potential usage ideas in their patent documentation - they're too busy trying to explain recesses, protrusions and engagements - but given there are several clamshell devices in their history, we'd be interested to see what eventual device might use this new design.