Not directly related to advertising - but extremely cool. This video shows off the powerful capabilities of a multi-touch sensing screen. The video looks like it's straight out of the minority report. It's incredible what they can do now. (Be sure to watch the whole video.)
"While touch sensing is commonplace for single points of contact, multi-touch sensing enables a user to interact with a system with more than one finger at a time, as in chording and bi-manual operations. Such sensing devices are inherently also able to accommodate multiple users simultaneously, which is especially useful for larger interaction scenarios such as interactive walls and tabletops."