Kayak has become my favorite website. We decided to come down this summer and put in "alerts" for several arrivals/departures. One day my wife called me on my phone, which I thought was weird since we were both in the house. She called me because I was upstairs and she didn't want to risk leaving the computer in case the deal disappeared (strange but true reasoning!). After weeks of seeing prices mainly in the $260-300 range, she found a ROUND trip price of $160 from Philadelphia. We purchased it immediately.
If any of you haven't used Kayak, my recommendation is to be a bit flexible with your dates and departure time. If possible, be flexible with your airports and # of stops. Finally, relax a bit and give yourself a few weeks to find the best possible fare. I found that they went up and down every day. The $160 fare that we purchased was never in their system for the first two weeks that we looked, and it has never appeared since. I am glad we were patient, but I am also glad that we jumped on it when we had the chance.