This proposal is a randomized control trial using innovative interactive health technologies to promote and sustain walking behavior among elderly patients. The technology uses an Embodied Conversational Agent (ECA), a computer character that simulates face-to-face conversation. The trial will be block randomized by literacy status and include an intensive two-month, daily contact intervention via a Tablet PC ECA in the subject's home, an automated telephone program, and then an in-clinic, kiosk-based ECA for an additional 10 months, to promote maintenance of walking behavior. The study will occur in 2 phases, a pilot phase in which 20 subjects will be enrolled for the purpose of pre- testing the intervention and all data collection instruments, and a main study phase in which an additional 264 subjects will be enrolled.