DFW International terminal:   
January 23 2008 - 2 hour wait in immigration line while TWO Customs/Immigration Inspectors handle 600 people waiting in line.

DFW customs lines
(Unretouched photo except for stitching segments of the panorama into one wide image; click image to enlarge)

A panaroma view of the 600 people in line Wednesday evening. It's estimated one-half of these folks missed their connecting flights.

Most flights were from Mexico, one was from Canada.

There were 4 roped snake/switchback line segments, each with about 125 people, PLUS in the hallway (picture: farthest, outside the rope area) they extended (to the right) almost into the gate areas (the line continues on the right deep into the connection hallway).

Only two inspectors were stamping passports. One of the guards/traffic managers said that there wasn't enough funding to hire enough inspectors.
Eventually they increased the inspectors to THREE.

In the picture above (4 wide-angle(17mm) images stitched together), the bulk of the crowd in the left half of the picture is not very visible - i handheld the camera above my head and shot blind, but the distance was so far to the other side, the mass of people blurs into a compressed perspective. Shutter speed is slow due to low light levels, thus people who are moving are slightly blurred. I did not take more due to the warning that my camera might be confiscated.

Hi-res version available. (email address displayed on my home page: sherwoodphoto.com)

DFW customs inspectors
Two inspectors to handle 600 frustrated passengers who are waiting impatiently just outside the cropping of this photo-- The lit signs offer false hope that more lanes are open/staffed.

Other Resources - this is a well known problem: