Google has really made an impact on the software horizon that the Internet has to offer. They have a whole area on Google called Google Labs. Most of their software is geared towards the Windows majority of the population, but every once in a while they have a very nice app for the Mac. Sketchup is one of those apps, a Mac 3D modeling program, in both a free and commercial version. Worth looking into for the FREE price, and upgrade if you decide to stay with Sketchup.