Managing large classes skillfully enables teachers to focus on their content and effective delivery. Here are some methods to ease the trial of taking attendance in large classes. 

Some Things to Try:

• Have students sign in at the door.
• Assign students numbered seats and have them sign a seating chart when it is passed.
• Cut a seating chart into segments and circulate them so that each student can print last their name. If you have a TA, have him or her mark empty seats on the chart during class.
• Take attendance at the end of class to discourage students from signing in and then leaving.
• Taking attendance at irregular intervals may suffice, especially if there is a clear policy for lowering grades when absences are excessive.
• Pass out coded Scantron sheets.  Have students use them to answer feedback questions that the instructor writes on the board.
• Periodically collect written "exercises" and make them the basis of discussion.
• Give a practice exam problem at the end of a lecture on Scantron sheets. This is both a way to take attendance and to test students' retention of the material.
• Collect homework one week and return it another; students must be present both times to get credit.
• Post alphabetical lists of names on the walls of the classroom at various locations and have students sign in.
• [Editor's addition:  Use personal response devices (clickers) to take attendance.]

Source:  Sallie Ives:  http://www.fctel.uncc.edu/pedagogy/focuslargeclasses/, Survival Handbook for Teaching Large Classes.