While instant messaging clients are frequently and widely used for interpersonal communication, they lack the richness of face-to-face conversations. Without the benefit of eye contact and other non-verbal "back-channel feedback," text-based chat users frequently resort to typing "emoticons" and extraneous punctuation in an attempt to incorporate contextual affect information in the text communication. Conductive Chat is an instant messenger client that integrates users' changing skin conductivity levels into their typewritten dialogue. Skin conductivity level (also referred to as galvanic skin response) is frequently used as a measure of emotional arousal, and high levels are correlated with cognitive states such as high stress, excitement, and attentiveness. On an expressive level, Conductive Chat communicates information about each user's arousal in a consistent, intuitive manner, without needing explicit controls or explanations. On a communication-theory level, this new communication channel allows for more "media rich" conversations without requiring more work from the users.