I find this article very interesting:
If you watch someone else lift their arm and eat the ice cream cone a subset of the same neurons also fire. Just watching other people take an action causes some of the same neurons to fire as if you were actually moving.
And related to web design:
Video at a web site is especially compelling. Want people to get a flu shot? Then show a video of other people in line at a clinic getting a flu shot. Want kids to eat vegetables? Then show a video of other kids eating vegetables. Mirror neurons at work.