ESP: The Experience Sampling Program
This site includes free, open-source software and documentation to conduct an experience sampling study using a PDA running Palm OS. The site is described by the author as, "ESP is a FREE, open-source software package for running questionnaires, surveys, or experiments on a Palm Pilot or compatible handheld computer. ESP asks questions of your participants and records their answers and their response times. The data may later be uploaded to a computer for analysis."