Thats right, legally download free Autodesk software including inventor, 3ds max and more.
I am a mechanical engineering student at Hofstra University and got an e-mail from the engineering department about this. I have already downloaded inventor 2008 and it works perfectly.
All you need is an e-mail address from your college and your good. Go to the link below, sign up and thats it! You get a 12 month subscription and when it is up, you just download the new one.
http://students2.autodesk.com/?lbon=1