The State Department is tweeting specific instructions for U.S. citizens to depart Egypt:

U.S. citizens who wish to depart #Egypt via USG-chartered transportation: call 1-202-501-4444 | email [email protected]
Over 2,400 Americans have contacted us requesting evacuation assistance in#Egypt. | More info:http://go.usa.gov/Y5t
We intend to evacuate approximately 900 Americans from #Egypt today and will continue evacuations on Tuesday.http://go.usa.gov/Y5t

Meanwhile, the FT reports departing businessmen, and repatriation of Egypt-based employees.