Spanair codeshares with a number of their Star Alliance partners and once in a while, the codeshare flights can be very reasonable, or in this case, extremely reasonable.
Fall fares to Barcelona and Madrid are currently available for as little as $340 r/t including taxes.
Booking is rather straightforward--just go to Travelocity, Orbitz, or Expedia, put in your city (many cites are part of this sale), and search for flights to BCN or MAD from September on.
To save time you can even constrain your search just to Spanair by using the airline preference tab located on the search screen of each of the sites above.
The flights, though sold by Spanair, are all on US Airways metal and book into W Class, meaning you earn 100% elite and award miles on most programs including United, Continental, and US Airways.
As always, book fast if you are interested--this fare will not last long!
- New Orleans: $396
- Philadelphia: $340
- Baltimore: $396
- Seattle: $569
- San Diego: $551
- Los Angeles: $502