Structure Synth V1.0 has been released. I have to be honest, I'm not exactly sure what this is - from the Structure Synth website: "Structure Synth is a cross-platform application for generating 3D structures by specifying a design grammar. Even simple systems may generate surprising and complex structures." Whatever that is, it sounds pretty rad, so I'm going to download it and play with it this afternoon.
Get it for free here:download (versions available for Windows Xp/Vista, Linux and Mac OS 10.5)