This paper describes PDAGraph, an event-driven, component-based visual programming language for power users of Handheld Computers or Personal Digital Assistants (PDAs) who are not necessarily professional programmers. PDAGraph is intended to run on a PDA and will give power users the ability to create customized applications, taking advantage of existing PDA applications and hardware modules (such as springboard modules available for the Handspring Visor). The language is component-based and ensures that the user can create only syntactically correct programs by placing and linking components or component items. There are external, user interface, and script components, all of which are reusable.