This video shows LucidTouch, a mobile device that is "pseudo transparent", i.e., it allows users to see their fingers through the screen. Users interact with screen contents using multiple fingers on the back of the device. LucidTouch solves a problem traditional touchscreens are facing: it prevents the user's fingers from occluding screen contents.

Find more information and a 10-page paper about lucid touch see:
- http://patrickbaudisch.com/projects/lucidtouch/index.html
- http://www.merl.com/projects/lucidtouch
- http://research.microsoft.com/users/baudisch/projects/lucidtouch/