Personal digital assistants are lightweight, inexpensive, and ubiquitous. Furthermore, they have desktop class operating systems features supported by industrial strength development tools. These devices provide an ideal platform for deploying a practical platform for I2C bus analysis. In this paper, we propose a low-cost, highly portable I2C bus analyzer on a PalmOS based PDA. We describe the hardware interface, the supporting libraries, and the PalmOS-complaint application. The proposed approach is flexible and supports the creation of additional bus analyzer applications by third parties. The example bus analyzer application described here provides three operating modes, passive snooping, active bus mastering, and active slave device emulation. Each mode function over number of user-selectable data rates.