Project@Hand?
http://www.natara.com/ProjectAtHand2/index.cfm
Advanced scheduling engine.
Organize your project using a hierarchical task list.
Integrated Gantt chart.
Project, task and resource lists are fully customizable.
Supports high resolution devices.
Supports devices with virtual graffiti areas.
Save projects on storage cards to free up memory.
Define and save multiple filters.
Beam projects to other handheld devices.
Print task information using TealPrint or PalmPrint.