Need a website for cheap last minute airfares in the US.

Try travelzoo.com. Also check last minute sales on travelocity.com

If you're near a USAir hub, sign up for their E-Savers e-mail bulletin. They send you a list of cheap fares for the upcoming weekend, weekly. Good luck!

Hotwire.com might also be worth a look. Just got a decent deal on short notice between two mid-tier airports (Harrisburg/Mobile.)

A lot's going to depend on where you're going to and from....

Also check travelocity, expedia, orbitz,
travelworm, hotwire, biddingfortravel, and priceline

rockbottomfares.com

site 59.com

www.lastminutetravel. smarterliving.com
qiko.com sidestep.com

Thanks for all the help. I had to call the airlines (Delta) because my son had a credit with them from a flight he couldn't go on in Feb. The cheapest online I could find fares to the 2 cities he's going to is $350. The agent was very nice and patiently found the best deal he could- $250. I always make my reservations online, but in the future I'm going to call the airlines just to make sure they don't have a better deal.