For those of you in the "get school out of the way" camp, unless you plan on going to grad school after your year off, good luck finding a job when you get back. Expect the search to take around a year, all while working some crap job to make ends meet. Usually your senior year of college is spent finishing up course work and searching for a job, interviewing, etc. I don't know many people willing to hire somebody who isn't going to be around for a year and you can't very well look for a job while you are in a foreign country. In addition, during school you will probably make some good contacts, contacts that you will probably loose if you let them slide for a year.
I would plan on going before you start college, or try to go during summer breaks. 3 months a year for 4 years = 1 year abroad and way you can try different places.
I waited a year to get a job and I don't think it affected me, IMO. I still think going during summer or taking a term/semester abroad is a better route