Just wanted to let you all know that if you happen to be a student or faculty anywhere in the world, Autodesk allows you to download their flagship mechanical design product, Inventor, for free, along with training material. (http://www.autodesk.com/edcommunity)
 
Visit this site for more information: www.autodesk.com/edcommunity
 
And also, check out my blog (http://2dtocivil3d.typepad.com/) on Civil 3D or my counterpart's blog on Inventor (http://engineeringeducation.typepad.com/) to get regular tips on features and other fun stuff.  
Have fun.
 
Sanjay