Have you ever looked longingly at your mouse, noting its underutilized input device real estate? Canon has, replacing that excessive unused space with a built-in calculator in its X Mark I Mouse, announced today for folks in the US. (If you'll recall, we spent a few quality moments with this guy in Germany last year at Photokina.) The combo device provides users with both a physical ten-digit adding machine and a numeric Bluetooth 2.0 keypad, which you can use seamlessly with a variety of apps, replacing the number pad now absent on many desktop and portable keyboards. The company's camera design team helped to create the hybrid input device, which also includes a trio of mouse buttons and laser tracking. Canon also announced its X Mark I Keypad, a full-size calculator with Bluetooth support that's powered by either AAA batteries or a built-in solar panel. Both devices will be available for $60 in August and September, respectively, and will ship in both black and white.