Register at the Flash Mob America's website to receive emails about events in your city or town. In addition, you can "like" Flash Mob America on Facebook and follow the announcements of new flash mob events across the country.
Sign up for an event and attend a rehearsal. Rehearsals last around four hours and may occur up to a week before the flash mob event. Alternatively, some events post the dance choreography online so you can still participate even if you are unable to attend a live rehearsal.
Practice the choreography as often as you can. It is important that you really have a firm grasp on the choreography to blend seamlessly into the crowd.
Participate in the flash mob event at the stated date and time, and have fun. Some events require you to show up early to receive a T-shirt or other costume to create a unifying look.