I'm sure this isn't nearly as relevant now the LHR has released there new 3d tools, but for those who bought the STL importer, and want to play with creating there own STL objects, this might be of some use. I stumbled upon this site today..... have I mentioned I LOVE open source??

http://sourceforge.net/apps/mediawiki/free-cad/index.php?title=Main_Page

Any since my background is in programming.... i love the programming API's and built in script-ability of this. I haven't installed it myself yet, but sure looks interesting.