Managing versions is a superb feature, which most users are not aware of. How many times did you save your documents under different names (mydoc.doc, mydoc-1.doc, mydoc-final.doc, etc)? I bet there were times you have ended up with a separate folder to keep all of your file editions.
All the above can be avoided if you would have been taking advantage of the Word 2003 version manager. To those of you who are familiar with the PLM (Product Life Management) programs, the concept of "multiple version" should be familiar and, I hope, a matter of everyday application. But Word has a little PLM inside already! Either you go to Menu-File-Version or press Alt-F – R on your keyboard, and you can get inside the version manager.
In this small window, you can save your document's current state ("Save now…") with certain comments about this version. The document, as it was in the time of your saving, will be stored and you can revert to it later (by going into "Version Manager", picking the desired version, and clicking "Open" in the form). This is very useful if you are unsure of formatting or content and want to be able to "take back" several actions. Remember, you can have as many "versions" of your document as you want – switching between them with just a few mouse clicks. It is also useful when submitting your documents for a review (which sometimes can take several back-and-forth batches) to keep track of every iteration for future reference.
Note that you can automatically save a version of your document each time that you close it.