As we know from search and rescue experience, accountability systems are for people safety and are used to keep track of personnel involved in an emergency response. Accountability is popular in emergency services however, not as likely to be found in the corporate setting. But, it is catching on.
A very comprehensive study was contracted by FEMA and the United States Fire Fighters Association which demonstrates the seriousness of accountability for responding personnel.  In addition to understanding new technology, fire associations keep track of actual statistics of near-misses and tragedies of losing emergency personnel on a scene. 
On small emergencies, accountability tags with our name, rank, skills, and agency are used. These tags are attached with Velcro to our helmets or gear. We must hand over one of these tags to a supervisor on small scenes.
On larger incidents, there will be a status/check-in  location. All responding personnel must stop at status/check-in to be accounted for and given an reporting location and assignment. There are many accountability tag tools available for purchase and use by any business. 
I believe accountability would be a beneficial part of any incident management operation in the business setting, as well. However, in my corporate experience, accountability is an after-thought, as in someone in charge saying ‘OK, let’s makes sure we can account for everyone’, but often the disaster is well underway and finding people is difficult.
Modern business practices expose us to not being able to find people. With the advent of flexible hours, working from home or remotely, heavy travel schedules, it defies logic to think we can actually account for everyone in a timely manner, especially during the crisis, when it counts most. It counts most because rescue is paramount and knowing who is missing and approximately where they might be is critical to a successful find and rescue operation.
A best practice of accountability during disasters is the care given to knowing where all personnel and their families are located. For example, the Air Force places great value on accountability. A new software system :… allows commanders and units to account, assess, manage and monitor the recovery and reconstitution process for personnel and their families affected and/or scattered by a wide-spread catastrophic event. 
 IOCAD Engineering Services. Date unknown. Inc. FEMA – United States Fire Administration. “Personnel Accountability System Technology Assessment“. Source (accessed 12-16-09) http://www.usfa.dhs.gov/downloads/pdf/publications/fa-198.pdf
 “National Fire Fighter Near-Miss Reporting System-Reports Related to Emergency Evacuation“. Source (accessed 12-16-09) http://www.firefighterclosecalls.com/1238644080Near_Miss_Report_-_Emergency_Evacuation.pdf
 “National Interagency Incident Management System Task Book for the Position of Status/Check-In Recorder(SCKN)”. Source: (accessed 12-16-09) http://www.epa.gov/Region6/6sf/pdffiles/ics_planning_status_recorder.pdf
 Accountability Tools. “American Trade Mark Dashboard Commander Tag Command Board“. Source: (accessed 12-16-09) http://www.chiefsupply.com/products_zoom.asp?find=http://www.chiefsupply.com/images/products/600/SSPDC.jpg
 Horine, Beth Kelly, Maj. 11-MAR09. “Accountability System Helps Leaders, Families During Crises“. Source: (accessed 12-16-09) http://www.af.mil/news/story.asp?id=123139161