Office and the "X"

You all might have enough experience with the newer Word and Excel file formats, but just in case you don't here is the primer:

• Starting with office 2007 (and now 2010) the default file format for Word and Excel is docx and xlsx. You may have tried to open these with office 2000. They won't open, unless you (or I) installed the file converter.
• So, once you have office 2010, you are now on the other side of  fence. If the person you are working with, or sending a file to has 2010, then life is good, but if they have an older copy of office, they might not be able to open your files.  If you are not sure the person has office 2007 or 2010, and you want to save all the nifty formatting you created in your word docX file, then save it as a PDF -- it's easy in office 2010
• You can choose to change your default format to word 2003 (doc file format), but I think our office got onboard with the newer office formats late enough, that we don't have to worry too much about that. That being said, I think you will still have a few people who say "I can't open the file you sent me", so what do you do? Do you reboot, check cables then call Chrisman? No, you save the file as PDF or as word or excel 2003 format.