SynchroMate (by Gibbs et al, 2005)
The SynchroMate fits snuggly in the palm of one's hand. It has a touch sensitive display and a small number of programmable buttons. It encourages serendipitous synchronous interaction by indicating when a message is being composed for you by a distant companion through gentle vibrations and pulsing concentric circles of lush colors on the display. The SynchroMate's buttons may be used by either curling the fingers over the palm (if the device is being used when hidden) or by using the other hand. Messages appear on the SynchroMate's screen. Other buttons will be able to send indications of mood, health, or need for a good hug.
Source: Gibbs, M.R., Vetere, F., Bunyan, M., and Howard, S. 2005. SynchroMate: A phatic technology for mediating intimacy. In Proceedings of the Conference on Designing for User Experience (DUX’05). 37–41.