What day of the week are you traveling on? We usually go down on Saturday morning (PIT/MCO) and you can't fool around, the seats go fast. If you're going midweek, you can probably wait for a good deal. My rule is if it goes under $200, book it. Rates have come down considerably in recent years. We paid around $270 in October 1999, that was the best we could get. Then it went down to around $240, now it's usually below $200.
USAirways is the only nonstop carrier that I know of. All the others require a connection.