If you walk and talk with someone, eventually you will synchronize your steps with each other.
Interpersonal synchronization of stepping happens when people walk side-by-side. Little is known about this, but it has practical uses in therapy. In 2009, this phenomenon was the subject of a study to help impaired people in rehabilitation. Subjects were paired together to walk on treadmills side-by-side. The result? People started walking faster to keep up with their partners.
Plus, as OK GO has demonstrated, it can be awesome.