At school, we're using the new 2007 version of MS Office products (Word, PowerPoint, etc). At home, I've got older versions. No big deal most of the time, except for when I save something at school and want to work on it at home. I'd better be sure to watch the format, 'cause the old software can't open files in the new format. What a headache, to get home with my file only to realize it's the wrong format and I can't read it!
But now I've discovered Zamzar.
It's a free file conversion service. Upload your file in Format A, and it'll convert it to Format B for ya, then send you an email when the conversion is done. How cool is that!
Obviously privacy is a concern for certain files, but if it's just a homework assignment for my Organizational Behavior class, um, I don't mind if someone reads it.