Hey as many of you should know, microsoft hosts a lot of discount programmes for students.
You can get a lot of their paid apps for free (Visual Studio 2008 pro being one of them)
And some of them are available for a discounted price( Office 2007 and Windows 7)
So what do you do to get a key?
simple, follow these steps:
1)Be a student (Uni/College only)
2) Depending on where you study, go to:
UK: Microsoft UK Education - Home - Ultimate Steal
US: Windows 7 US Online Store - Student Registration
3) enter your college email
4) Check your college email inbox
5) enjoy your Windows 7 for 30usd/gbp!