Bricksmith is an open source application that allows you to make awesome virtual Lego models on your Mac. It’s a bit like a complex, tricked-out version of this LEGO iPhone app concept.
Bricksmith was created by Allen Smith. The application includes a parts browser, a full Lego color palette, drag-and-drop building, and more. It’s been around for a few years, but an updated version has just come out. The new version boasts added functionality and a sweet minifig generator.
You can download Bricksmith 2.0 for free from Sourceforge, but you have to have a Mac with OS X Tiger (10.4 or later.) Happy virtual bricking!