This work opens the door for a great deal of potential future work. In particular, there are several possible user studies that could be carried out using GalvaPhone. It would be very interesting to use GalvaPhone to research the following issues:

• Are certain combinations of self-reported emotion and arousal more common than others? For example, do users tend to be more highly aroused when they report that they are feeling angry, as opposed to reportedly feeling sad?

• Are phone call recipients more likely to accept phone calls from callers who are highly aroused, as opposed to those who are more relaxed? Does the call recipient's current emotional state, or arousal level have an effect on how likely he is to answer the phone? Are call recipients more likely to want to talk to people in similar affective states, or different affective states than their own? How much of a role does the caller's identity and his relationship to the recipient play in making these determinations?

• Does the interaction between emotion and arousal play a role in a recipient’s likelihood of placing or answering a phone call? Do people usually only place phone calls when they feel a certain way? Does the act of placing a phone call in the first place cause someone to have a higher arousal level?