Nokia Research showed off “ForcePhone” in Helsinki this week, which is a prototyped Nokia N900. The devices let callers send vibrations to each other by squeezing the phone during a call. The prototypes were tested by three couples in long-distance relationships.

The Nokia N900 prototypes can pick up four different intensities of pressure which translate to the appropriate vibration intensity. Perhaps during an argument, a level 4 squeeze of the handset lets the partner know nonverbally.

The three couples used the ForcePhone as their primary phone for one month for testing. According to Technology Review, the couples found some creative and unusual uses for the devices.