Tried it just now. http://flisea.com was confused when I entered "San Francisco" as the destination; I had to enter "SFO" when what I really wanted was "SFO | SJC | OAK" and it never returned any flights. Adioso has room to improve their price search but the user interface is just what I want to use - no error messages, just does the best it can with what you give it.