Just noticed the tags feature in Windows 7, which corresponds to keywords in Office 2007. It would be possible to forego folder organization and just use tags. Folders are an old fashioned way of organizing files, and we really should no longer be using these today. With tags we could also bring together files which would normally be stored separately, like photos and emails.
However it isn't possible to add tags to other formats like pdf, rtf or odt. Although keywords can be added to Openoffice files within Openoffice, these are not recognized as tags by the file manager in Windows 7. That's a pity.