Looking at doing some experiments that may require 2.5D in Flash. These two libraries look helpful:
coordy is a Flash layout toolkit that allows you to easily organize items in various layout patterns.
The first time I experimented with 3D flash is a very clear memory. I was young, and naive, full of hope and romantic dreams. Her name was Sandy.. 3D… 3.0, and she tempted me with her new thinking and careless and free download. I learned a lot about 3D from Sandy, and to this day, I reminisce of our beautiful times together. But sometimes love just isn’t meant to be. The pressures of designs needing exact dimensions on displayed objects, vector graphics, and perfectly predictable placement of objects tore us apart. 3D just isn’t how most designers design. They think they want 3D, but the moment something has lines that aren’t perfectly parallel to the edges of the browser (as 3D often does) they are not amused. And let me tell you, telling an illustrator that he/she should learn 3D math so that they can predict how your program will display their objects when moved around does not go over well.