The end of folders?

Slashdot has an article today about the death of folders.

The idea is that rather than placing a file in a folder, you add metadata about the file, describing it's characteristics. The advantage of this is that you can have multiple characteristics, so you can say that a file is related to "Family", "Photos" and "Funny" all at once. Then when you browse the disk, it shows these categories as virtual folders.

Gmail does this and I've heard lots of positive feedback. I think it sounds very promising.