It would be really useful if Office documents (e.g. Word, Excel) would have an option to increment the file version every time a document is saved and closed.

For example, if you opened
Session1_ExtremeProgramming_Access97to2003_AdamCogan_v3.ppt,
made a changed, saved and closed the document, the filename would update to
Session1_ExtremeProgramming_Access97to2003_AdamCogan_v4.ppt.

This would help ensure that the latest version is being used and that you can determine at a glance which version of a document is the newest.