I recently started using Google Sketch-up as I've been learning woodworking. Its not the first time I used a CAD or 3D modelling application. I went to high school in a blue collar town, and the local industry bought a bunch of CNC machines for the school. As part of that we learned how to use Auto CAD. I also used lightwave 3D, and 3D studio max (through less than legal means...)

but these latest programs are really making the process dead simple. I'm excited to see the stuff people make with these applications as they become easier to use, and more prevalent.