We have just released a beta of Trabber for users from the States. Give it a try and let us know what you think about it: Trabber U.S. beta
Hope you find it useful if you are looking for cheap flights in the U.S. Trabber started in Spain some months ago followed by Germany. It has been very well received by users from both countries.
At the moment, Trabber US searches three major online agencies (Orbitz, Expedia and Priceline) and also all the airlines from Europe included in the Spanish and German versions (Iberia, Lufthansa, etc.).
From now on we will work on including American airlines to the list of providers.