A graphics and physics demo that shows Blender Game engine (available in Blender 2.48) in action:
Blender Game Engine: Bathroom demo from martins upitis on Vimeo.
Blender 2.47 has been released and is essentially a bugfix release. Blender is the free open source 3D content creation suite, available for all major operating systems.
You can download Blender here: Get Blender 2.47