Got a lot of maybe-one-day useful CAD Programs, with all the hassle involved, just to find out that Art of Illusion can export to CAD, courtesy of RepRap...
Remember, you have to start AOI as Root, to install the Plugins necessary, on Ubuntu Lucid, so it's command line time:
# sudo su
# cd /usr/local/ArtOfIllusion
# sh aoi.sh