Site to see: Traveas
There are plenty of travel sites with flights available. But what makes this site different is that after searching for information on a flight, you can then track it multiple ways.
If you're picking up someone at the airport, you can get an alert. If you're a traveler who has just been bumped, you can get on the tracking list to find out if this is a flight you can hop on.The site is in beta and will soon charge for the service, but this is the sort of service that would be nice to have from the airline industry.