Spilt the group up into several smaller groups of about 4, and choose one group to go first. One player is picked from that team, they are then blindfolded, meanwhile the other groups have arranged an obstacle couse of tables. When the course is ready the blindfolded player is spun around. A stopwatch is then started, the blindfolded players team must then direct them using verbal commands (left, right, stop) through the course, each time they walk into a table, 5 seconds are added to their time. When they get to the end, the stopwatch is stopped. They return to their team and the next member is blindfolded, the tables are moved again and this player takes their turn. When everyone from each team has gone the teams times are added up, the quickest team wins.
Source: From the original site.