[Alan Anderson]

Establish a "counting order" with each person aware of and responsible for their neighboring numbers so it takes almost no time to determine if everyone is present. Plan ahead to be able to split up quickly into smaller groups when necessary. Make sure everyone has a list of cell phone numbers.

Designate someone who isn't traveling as an emergency contact. Having a resource at "home base" can make it a lot easier to keep people at home informed as things happen.