This Vibetonz system seems to provides cell phones with a new feature: haptics. More explanation here (.pdf)

VibeTonz is intended to enable users to download different vibrations the same way they download ringtones now. The vibrations could be used to add sensory depth to emoticons sent by instant messaging, or to provide sensory feedback when navigating by a global positioning system

Here is the interface to compose the vibrations from MIDI files: