The sliding keyboard has a lot of fans, but every sliding phone seems to have its own rules. It seems HTC has take the game to a whole new level with their new pattent which would allow a device to slide in horizontally and vertically to reveal the dialpad in one direction and then the keyboard in the other. the idea is nice, but implementation may be a bit tricky. The mock up image above saw photoshopped based on the sketches which HTC used to file their pattent. You can see what no matter which way the keyboard slides (even when closed) some part of the keyboard is exposed.
Lets just hope that HTC created this awkward sketch simply to keep us guessing about what they are really planning to use this pattent on. There are currently a few devices on the market with sldie two directions, but they have a distinctly seperate dialpad and keyboard.