Recently overheard on the NZOSS mailing list:
Fun: my version of OpenOffice doesn't know what to do with .odt files. (I'm using Debian stable, y'see.) But "file" told me it was a zip archive, so I unzipped it, found a file named 'content.xml' inside, stripped the XML tags from that, and read the resulting plain text file. I like .odt files already!
<cynicism>Yep - sure sounds like linux is ready for the desktop...</cynicism>