Solve Word 2003-2007 incompatibilities

Microsoft changed Word's format with version 2007. Word documents created with Office 2007 are given the file extension .docx, which is a different standard from the .doc format of all previous versions. (At least the suffix does you a clue that you are dealing with two different animals.) The downside is that if you have only Word 2003 or earlier - and I have Word 2000 still chugging along happily on one machine - you cannot open the new format. Fortunately, there are several solutions.
1. If you're using Word 2007, you can still save your files as .doc files so that anyone can read them. To save an individual file this way, in the Save As dialog box's 'Save as type' pull-down menu, select Word 97-2003 Document. You can also set that format as your default. Click the Office logo in the top-left corner of the Word screen, then select Word Options (bottom right of the dialogue box that pops up). In left pane, click Save. In right pane, for 'Save files in this format,' select Word 97-2003 Document (*.doc). Click OK.
2. If you're using Word 2000, 2002, or 2003, you can download and install the Microsoft Office Compatibility Pack for Word, Excel, and PowerPoint 2007 File Formats. The downloads are free.
3. Another option is to use OpenOffice.org as your word processor. Version 3 recently released can open .docx files quite happily. If you have only an earlier version (hey, it's a free download), you can use the updated Word Viewer from the Microsoft website and use it to open the .docx document. This document can then be copied and pasted into OpenOffice. Another possibility is to use the free online service called docx-converter which converts documents into the format readable by OpenOffice.
I should note in passing that OpenOffice's default format is called "open doc", which saves files with the extension .odt. This format can be read by virtually every word processor, even including Word!