What's it for mate?
If it's just general drawing I'd recommed Google Sketchup
http://sketchup.google.com/ It's free and very easy to learn - It's what I used for the colour drawings in the book.
If it's more technical stuff there's DoublecadXT
http://www.doublecad.com/Products/Do...0/Default.aspx again it's free and very like Autocad, which might be a drawback - it's quite difficult to learn.
Cheers
Chris