Daily dairies, also known as experience sampling methods (ESM) or everyday experience methods, are a common methodology utilized to provide insight into momentary psychological processes. Traditionally, such studies often have utilized paper-and-pencil surveys administered several times each day over a span of several days or weeks. However, advances in technology now allow these studies to be conducted using palmtop computers (i.e., personal digital assistants; PDAs). Three software packages for running these studies on the Palm operating system were explored and compared on a number of features Specifically, ESP (Experience Sampling Program, by Feldman Barrett & Barrett, 2001), iESP Version 3.2 (Intel Experience Sampling Program, by Intel Research Seattle & the University of Washington Computer Science and Engineering Department), and PMAT Version 2.0 (Purdue Momentary Assessment Tool, by the Military Family Research Institute at Purdue University) were examined, with their key features compared. These advances in software for running diary studies include a number of features that provide researchers with methods and information previously unavailable in diary studies and may expand the range of possibilities in diary study designs.