Principle of autostereo display
One of the first Java applets
I ever wrote was to illustrate
an idea for an
(a display that lets you see in stereo-3D
without needing to wear stereo glasses).
The basic idea is to animate
an image of a fast moving picket fence
on a special purpose LCD screen in front of your monitor.
At any moment, each of your two eyes, looking through this virtual picket fance, will see parts of a different image. The image of the picket fence itself whizzes past your eyes so fast that it blurs out and you don't see it (click on CYCLE in the applet to see the principle).
The novel thing about this approach is that it can accomodate an observer at any position and any dstance away from the screen. In the applet at right you can drag the guy's head around to see how the display adjusts to different head positions.
The interesting thing is that this applet took only about a day to write, but we were able to use it to get funding to build the actual device, a multi-million dollar project.
Which convinced me that Java applets can have an impact.