[Image: http://cdn.techtavy.com/images/gmail7.png]
Once all your documents have been tagged (added to collections) you can pretty much filter them as you please and know their 'directory' the whole time. It's pretty much like Libraries in Win7.
The best part is that you can share collections. Say you wanted to share a couple of files from school and work to your brother... using Windows, or any 'traditional' OS, the usual would be creating a new directory (or zip file) called 'Brother' and mail it to him. Well with collections you can simply add a a new tag to these files and share the collection right away, no need to copy and paste or waste space and time!
[Image: http://i.imgur.com/KIO70.png]
I guess my point is that tags are better than files in many ways, they make information easier to manage and share. What do you think? Is this the future of computing? Tags are commonly used in internet services but not so much in file management, I think it should change.