Google Docs lets you manage versions of Word and PDF documents without changing the document link....
Ahhhhh.... which version is the right one? With apologies to John and Patty
How many times have you created an agenda and sent it out to a group only to have to change it moments later and then resend the agenda?
Or added links to a PDF document in numerous other documents and your Website? And then having to redo all links because the PDF was updated?
Google lets you update your Word docs, PDFs (in fact any file type)
without changing the original URL.