There are not so many web apps for the iPhone and iPad. On this note, recently I came across a pretty jaw dropping 3D rotating molecules (live demo) which works on the iDevice. According to the developer, the whole 3D rotating effect was achieved through css3 and he was also says
To accomplish this in CSS, we take advantage of a technique called “billboarding”. Billboarding involves rotating an object (in our case, each of the colored balls), in such as way that it remains facing directly at the camera at all times. This is a fairly common technique in the world of 3D gaming, used to render things such as trees and grass — and in our case, it gives the illusion that the circles are really spheres.
A very good effort from the developer. If don’t have Safari web browser, watch the demo video of the 3D rotating molecules after this break.