One of my favorite travel sites is
www.travelzoo.com. You can sign up for weekly email newsletters where they will highlight some pretty good deals. If you can be flexible with your dates you can find some decent deals on there, especially with the big airports (JFK, DC, Boston, LA). I was able to go to Paris my junior year for spring break for 200 bucks. My senior year I remember seeing a deal to Puerto Rico from NYC for like 109 round trip and a bunch of the sisters were thinking of going for our long weekend break in October. Definitely worth checking out and it's also a good place to check for last minute deals for cruises and hotels.