Here's another surprise from US Airways --->
Frankfurt (FRA) - Jacksonville (JAX):
384 Euro R/T in November.
These special fares usually last for only a couple of days.
Last month there were similar fares from Brussels. Then they went back up to 500 €. Then down again to 400 €. You have to follow it up closely.
Go to usairways.com and click on the flag of your country, at the bottom of the page.