Make sure you bring a few hula hoops. Have the kids/people make two or more circles (depending on the amount of kids/people). Have everyone in the circle hold hands and introduce the hula hoop into the chain of people. The object is for them to pass the hula hoop around the circle without breaking the chain. They can do whatever is needed like stepping through it but they can not break holding hands. If they do it quickly then tell them that it has to go back around the other way. If the kids/people are real good then bring small hula hoops and have them use those.
Be creative and change it up a bit or add other items for a more exciting game.