An irritant of the Office 2007 era is that some people insist on sending you files in that $**$% program's default format: .docx, .xlsx, or .pptx. And these same people won't comply with your request to save the frakkin' thing in a reasonable format. (Like PDF. Nice, small, and I can't edit them to make you look completely ridiculous and send the result to all our friends. But that's a subject for another post.)
I've really been tempted to send my responses in Swahili. Transliterated into Urdu. Unfortunately, I don't speak Swahili, and my Acme translator's instruction book is in Hindi. So that's out.
Short of ending friendships and associations forever, it's now possible to read these files with version 2.3 or better of OpenOffice.org. You can't write in those formats, unless you want to do some minor hacking, but you can read them and convert them to a reasonable format.
Say as OpenDocument (.odt). Then send it back to them and when they complain, point out that it's an open standard, and Microsoft should be able to read it. (Not my idea.)