Since cell phones still rely on land lines to get between towers and long distance lines to get between cities they are vulnerable there just like land lines. They are more vulnerable to overloading because the requirments for cell phone peak usage are lower than land lines (can't remember the numbers at the moment). An interesting observation from 9-11, while most people's cell phones didn't work (mine included, had to tell my wife to get on a main steet and walk the direction toward our home and I drove the street until I found her), text messageing seemed to work fairly well since it requires much less bandwidth (remember a cell phone ties up a connection as long as you talk where text messageing you compose the message then hit send then it makes a connection, spits out a few bytes and disconnects). I made sure both of our phones from then on could do some form of text even if it did cause an extra fee when used. My current phone and most sold now have a gps built in (anyone know one what can be plugged into a laptop/pda and be use the gps function that way) and for years the e911 systems would give the disaptcher both the cell humber and the number and address of the cell tower it was connected to so the rescue crew could go to the tower and start looking in a circle. I installed a bunch of those e911 systems in 96-97.