Touch screen technology has been quite newsworthy in 2007 - Jeff Han's large-scale multi-touch screen, Microsoft Surface, the Apple iPhone, and Synaptic's Onyx concept - to name a few.
But overlooked amongst these was the news this summer of the Microsoft/Mitsubishi collaboration on a two-sided touch screen. This technology directly addresses one of the critical usability issues with touch screens - the user's hands blocking his or her line of site with the screen. The two-sided touch screen optically tracks hand movements on the back side of the display and mirrors them to the front (see images). It is likely that this solutions solves one problem, and introduces user usability challenges with working "backwards"
Incidentally, this is the first post I've done using the new Windows Live Writer, rather than directly via Typepad's site. Writer provides some nicer features and editing capabilities.