Did you see Avatar yet? Then you probably remember the grass that glowed when you touch it. Sully, the main character surely had a lot of fun with it. Someone, obviously unsatisfied with being unable to ride a six-legged horse, decided to go the DIY way and make his own glow-when-touched grass.
Here’s a video demo of the grass in action and also a quick peek under the hood:
As you can see, it’s not as impressive as the real thing (or rather the realistic 3D render thing), but it’s a pretty good proof-of-concept. Now all the creator needs to do is to upscale the project and do a Tree of Souls. Or a floating mountain – I think that will be pretty impressive too.