The Shriners of North America are likely one of the best known Masonic organizations in America. Many people do not know it, but to be a Shriner you must first be a Freemason.
The Shrine is involved in many philanthropic pursuits. It's greatest being their burn and orthopedic hospitals for children.
Shriners participate in parades in their local communities to raise awareness of their works with children, and to promote the organization. Members will ride motorcycles, miniature cars, play in bands, but probably the most recognizable participants are the Shrine clowns.