I've learned the best way to learn how to apply for jobs: post one yourself and read the resumes.
Well, I'm not quite at that stage. I am compiling the resumes. Here are a few hints:
1. Send your resume and cover letter in PDF format. That's the easiest and most universal. Everyone can open PDFs, on any system, and they are pretty much always compatible with everything.
2. If you wish to send a second format, send a .doc or a .rtf.
3. Do not send weird formats from open-source software. Hell, I am a huge proponent of such programs, but they have their time and places. Sadly, cross-platform resumes are not one. Create them in a non-Word program and save them as PDFs.
4. Give people options. Send a PDF, a .doc and post your resume online.
5. If you have Office 2007, good on you. MAKE SURE TO SAVE YOUR RESUME AS AN OLD .DOC FILE! I can not stress this enough. If you send it to someone who does not have the latest version, they will not be able to read it.
Now, as to why Microsoft did not make this backwards compatible, I'll never know. Nor will I understand why they didn't, I don't know, send out a patch to everyone using Word. (Find me someone who would say, "no, I'd rather not be able to open files people send me thank you" and I'll find you a fish with a bicycle.) But, no, they have a "pack" (read: "patch") you have to download yourself, and for some ungodly reason a wee extension which should be a few hundred kbytes to convert xml to an older .doc format is 28 megabytes! And you have to restart for it to take effect.
It does, surprisingly, seem to, I don't know, work.