Here's a novel idea -- turning one's standard, non-tablet PC into a tablet PC. Hanwha Japan has just introduced its incredibly useful Duo for Laptop device, which sits gently atop one's laptop display and tracks digital pen movements via Infrared and ultrasonic technology in order to add doodling functionality to LCDs that were never designed to understand touch input. The only limitation -- and it's a big one -- is that this seems to only work with lappies possessing a 15.4-inch display. If that's kosher with you, you can snap one up for ¥9,980 ($101), or if not, you can just wait 'til these are announced for netbooks, ultraportables and desktop replacements.[Via