Introduction
SketchyPhysics is a physics plugin for Google Sketchup. It combines a simple and easy to use interface with the power of a fast and accurate physics library, the Newton SDK.
Current version is SP3x available here:
http://code.google.com/p/sketchyphysics2/downloads/list
Forums: http://forums.sketchucation.com/viewforum.php?f=61
Wiki: http://sketchyphysics.wikia.com/wiki/SketchyPhysicsWiki
Source code for the plugin is in the install.