Starting with Flash Player 10 Adobe introduces the native 3D calculations methods for Action Script 3.0 . This calculations are faster than scripted 3D trigonometric calculations. Papervision 2 uses this native 3D clases and I explored them also. Soon Adobe will release Flash Player which will use hardware 3D acceleration but now the most effective way to use 3D in Flash are this native 3D methods.

Mapping Flash video to 3D objects
http://www.adobe.com/devnet/flash/articles/flash_video_3d.html

Culling
http://help.adobe.com/en_US/ActionScript/3.0_ProgrammingAS3/WSB0132CAB-C91D-4cb4-9A47-394C85677E40.html

Projecting 3D objects onto a 2D view
http://help.adobe.com/en_US/ActionScript/3.0_ProgrammingAS3/WS36223081-8938-4b45-BB89-F1F8B1A52E4E.html#WS0D64676D-1BCC-40f0-9A23-F19F4A0D8A6C
http://help.adobe.com/en_US/ActionScript/3.0_ProgrammingAS3/WS36223081-8938-4b45-BB89-F1F8B1A52E4E.html

Exploring the new 3D features in Flash CS4 Professional
http://www.adobe.com/devnet/flash/articles/3d_support_08.html

Performing complex 3D transformations
http://help.adobe.com/en_US/ActionScript/3.0_ProgrammingAS3/WSA340940C-A537-450c-8069-A4A052A98CAA.html

Documentation for PV3D 2
http://www.flashbookmarks.com/PV3D-GreatWhite-DOC/

Also FP10 native 3D is used by Away3D Lite. Some more info here:
http://flashflex.com/harnessing-fp10-power-with-away3d-lite/
http://away3d.com/