First of all, I don't really understand why people lie on their resumes in the first place. Are they so brave and bold that they think they won't get caught? Or are they so self conscious and lacking in confidence in their real life experiences that they must hide behind lies? Either way, it's sad, it's wrong and it definitely doesn't make the job search go more smoothly!
A community college instructor served on a search committee for an English instructor. One of the candidates had been teaching as an adjunct and was pretty much a shoe-in for the available position. However, in reviewing his resume, someone noted a presentation the candidate claimed to have given at a professional conference that the committee member had attended...and had no recollection of even seeing the candidate there. (Did anyone else just say, "Duh"?) When confronted with this resume fabrication, the candidate argued that he had submitted the proposal, the proposal was accepted, but that he was not able to attend due to financial reasons. In his head, he really didn't think he was lying.
So, here is another reason people lie on their resumes...their ethics are operating in shades of gray. My recommendation, be above reproach! For example, you may view yourself as someone's administrative assistant, but if you really are just a work study student, you need to list your true title unless otherwise established with your supervisor.
Basically, there are much better ways to make your skills and experiences stand out through your resume without embellishing or outright lying on your resume. Check out this CareerBuilder article for statistics regarding how often liars get caught...and subsequently not hired. The guy at the community college, the shoe-in, the known entity...dude didn't get the job.