There are some really good fares currently for the Los Angeles – San Francisco and return route offered by Virgin and American. Many dates are available.
VALID FOR TRAVEL COMMENCING ON EACH TRIP ON/AFTER
03APR 13. TRAVEL ON THIS FARE COMPONENT MUST COMMENCE BY
MIDNIGHT ON 08JUN 13.
Now this is not mileage run material (although AA may have a per sector bonus?) but fares usually range between $90-$200 (one-way) for that sector. It's a good deal and worth to look at though if your travel plans involve this route.