Okay, let's say that you're not a consultant and that you don't ever plan to be. Let's say instead that you are seeking employment. Having once worked at an employment agency, I have written the following advice to you from my former headhunter's perspective:
A resume should be presented in Word and never in any other format because Word is today's Lingua-Franca of the business world. Stay with that, and only that.
Be careful of which version of Word you use. Microsoft's Office Word 2007 can save documents in a format ending in .docx which cannot be read by some earlier versions of Word (Microsoft strikes again), meaning that it can't be read by the version of Word that I, your friendly employment agency, just happen to have. Make sure you use a version of Word whose files can generally be read by anyone. This would be Word 6.0, Word 97 etc. Do not use the latest and the greatest.
Do not use Word-Perfect or any other format. At "this" agency, I don't happen to have a copy of Word-Perfect on my machine and it's a troublesome nuisance to extract your resume from some file that was written in Word-Perfect, or in any other format for that matter.
I don't want to take the time. I might be able to afford the time to do it, but I do not want to because I have a full load of other resumes to look at and I need to look through all of them. Make things hard for me with your resume and your resume will simply be put aside.
Do not send your resume as a zipped file. If your resume is so large that zip file compression is warranted, your resume is too long. Also, again, I don't want to be bothered with having to extract your resume using Win-Zip or whatever else it takes.
Make things as convenient for me as possible. Send your resume only as a Word file. (Have I said this enough times already?)
Don't try to impress me with your word processing wizardry. Keep things conventional. Use only conventional formatting.
When I present your resume to a client, I have to guard your confidentiality. That means I have to modify every resume I select. I have to be able to modify your Word file and even if you are a word processing expert, I most definitely am not.
Do not arrange your resume in two parallel columns, newspaper style. Don't include any illustrations. One resume came to me organized in two columns and was replete with several illustrations. Then, for reasons still unknown to humankind, the resume file turned into scrambled eggs when I tried to remove the name and other identifying items from the header. It's my guess that there must have been a lot of links in that document that got messed up when I tried to revise the header. I had to judge that resume to be useless.
Again, make things as convenient for me as you possibly can.
One more point about confidentiality: Don't blow it for me by putting identifying information anyplace but in the header. For example, don't include your ham radio call letters somewhere in the body of your resume's text.
There is more to come.