where can i get Auto-cad/ cad programs?

I'm looking for some computer aided design programs to help me put a design of guitar into practical measurments... (at the minute it's all just rough sketches)... Anyone know of any freeware version, shareware etc? I wouldn't condone pirated/ warez/ cracked programs, but I'm certainly not going to stop you...:D

i think
intellicad has a free version that doesnt have all the bells and whistles as a 3000 dollar autocad program.
i have never downloaded/worked with it but have read posts about it in other forums...
if you dnload it and work with it, please let us know what you think.
thanks
-michael