The other night while at the ref desk, one of my regular YA patrons ran into a little snag; he was meeting with his tutor, and he needed to print out a couple of essays. Problem was, he composed the essays using MS Works (which comes free with most Windows computers), and he couldn't open it on our computers, which run Word. Now, you should be able to convert the file using Word and its conversion setting, but for reasons unknown (security? converter not loaded/accessible?), this didn't work for us (and he didn't have time for me to screw around trying to figure it out).
After a quick search I found, and decided to try, Zamzar, an online file conversion tool. And although there's an "email step" that the service could well do without, the files were converted without too much fuss. Crisis averted.
Zamzar covers a wide variety of file formats, and since it's free and operates online and doesn't interfere with your hardward/software/security config, you might want to keep it in mind for patrons using your public access machines.