Click on Real-Time Flight Information above. The Flight Tracker site gives the current status of any flight between major cities within the United States. You can find out the plane's location, altitude, speed, and estimated arrival time among other things.

First try "Track a Random Flight". Click on either the text or graphical version, then click on "Track Flight". (The graphical version is slower.)

If you know a specific flight number (for a flight currently in progress), try tracking the flight by airline and flight number.

How current is this information that is provided?