Formerly known as "Memorial Day Murph", we tend to always be open for a group event of tackling the workout "Murph".
It is: 1 mile run, 100 pullups, 200 pushups, 300 air squats, 1 mile run. Optional to wear a vest while doing it as well. Often this is DONE BY TEAMS/Partners to complete and break it up into rounds of Cindy (5 pullups, 10 pushups, 15 squats) until completion.
If you want a shirt and to support the official event: http://themurphchallenge.com/