I've never used it, as I've never seen the possible savings worth giving up all control over airlines and times. You also are much worse off if you miss your flight and you're on a priceline ticket, as they're going to assume you just wanted to take a later flight.

That being said, if I had a lot of time and a little money, it could be worth it.

There was a good discussion board out there where people posted what they were bidding and what was being getting, I mainly looked at it for the hotels option, but I assume they did flights also. I can try and find it if you're interested.

Matthew