<qa>  What is the second minor arm still open for enrollment?Background. We have already completed the original, major arm of this protocol a natural-history study of craving and lapse. Still open for enrollment is the second minor arm a within-subject trial of PDA-based treatment-task reminders. In the third arm there will be enhanced assessment of mood, stress, and geographical location to further study craving and lapse. All arms of the study have developed from either or both of two aspects of the original arm: 1 Our growing appreciation of the technical possibilities of electronic data collection in participants daily environments, and 2 our growing interest in having participants provide descriptive data about the day-to-day experience of addiction and recovery. 