i will have taken 3 years off, assuming i get in this year:
worked as assistant to a very famous epidemiologist, helped her write a book, spent 2 months on research fellowship in japan, ended terrible relationship with college boyfriend, taught SAT and MCAT for Kaplan, worked for an asbestos law firm (medical evidence - kind of boring but pays well), took physics and english pre-reqs at night school, volunteered at local free clinic, grew up a lot...
taking time off has been great for me. i feel a million times more prepared for the challenges of med school with some real-world experience under my belt and a sense of what life is like when one isn't in school.
be warned though, the job market is sh#% right now, despite what you hear about the economy being on the up-swing. it is hard to get research jobs without good connections. if you take time off, you may find yourself doing work you don't really like.