" wrote in
ps.com:

Just wanted to thank everyone for their responses. Quite fascinating
stuff here. Thanks again.

Also, I was watching United 93 and they kept using the term "squawk".
I looked it up in a few resources mentioned but since I have no
aviation experience couldn't quite grasp the meaning. What exactly is
a squawk and what is it's function?

And you can listen to this online!!??? Awesome. anyone know of some of
the better sites?

If it were me, I would pick one of the "Top 30" from an airport near a
place I am familiar with - near where I live or where I've been in the
past. There are lots of good options - New York's JFK, Boston's Logan, and
Orlando (everybody's been to Disney, right?) Being from New York, KJFK is
an easy pick for me, but there are plenty of cities up there that might
work better for you.

"Sqauwk" refers to the transponder code assigned to an aircraft. Most
airplanes have a transponder in them that communicates with Air Traffic
Control (ATC) Radar. Certain areas of the country require a plane to have a
transponder for entry, but less populated areas do not require it.

Most modern transponders can communicate both position and altitude back to
the radar system. Some of the new ones even have two-way communication
where other traffic and weather information is "beamed" back to the
airplane's system.

In order to identify a specific airplane, ATC will assign a "sqauwk code"
for the pilot to enter into his transponder to uniquely identify that plane
to the system. The code is typically a four digit number. Even
"uncontrolled" airplanes with transponders squawk a specific code (1200)
and appear on the ATC radar screen, even if they are not talking to ATC.
This allows ATC (and other planes with anti-collision systems) to "see"
them and ensure that they don't fly too close to them. There are also a few
"special codes" that pilots can enter into their transponder to alert ATC
to certain types of emergencies (like a radio failure or hijacking, when
telling ATC about it may be impossible).

Enjoy!