The MIT campus can be a bit bewildering for outsiders (possibly also for insiders), so here are some directions to the event at 66-110 on the MIT campus:
66-110 stands for room 110 in building 66. Building 66 (also called the Ralph Landau Building) is on Ames St in Cambridge. The street address for the building is 25 Ames Street. If you're coming from Kendall Square, walk away from the Longfellow Bridge (keep the Kendall Hotel on your left and the Marriott on your right) down Main St. until you see Ames St. Take a left on Ames (the Koch Institute is right on the corner) and walk 2 minutes until you see the MIT List Center on your left. Across the street on your right is building 66. The side of the building that you'll enter comes to a sharp point (66 is shaped like a large triangle). Walk into 66 from the edge facing Ames and continue down the hallway (you'll see classrooms on your left and labs on your right) until you reach an open area. Room 110 is in the corner of this open foyer. There will be a large poster board with 'MIT Communications Forum' outside the room, and you'll see posters for the event by the door.
(Thanks, Cora, for the directions!)
ETA: Info about parking! A list of the parking lots near MIT: http://web.mit.edu/facilities/transportation/parking/visitors/public_parking.html. Apparently the lots at 4, 5 and 7 Cambridge Center are the closest to building 66. Otherwise there is metered parking along Memorial Drive, Ames Street, and Amherst Street, if you're lucky.