Open season: GTD for Palm

My pal Jon develops applications for Palm devices.  He’s kinda looking around for a project and, inspired by Cat’s Access app, I’m trying to convince him to make a GTD app for the Palm OS.  I’m not a genius about software design though.  I can barely use stuff.  I know what I want, but I’d love to hear what you would want in such an application.

So, if you had the opportunity to design a GTD Palm application from the ground up, what would it look like?  What kinds of features would you include?  What would the application hook into…contacts, datebook, what else?  What other apps (Palm or otherwise) would you prefer it play nice with?

From my point of view, simpler is better.  I’d just want an app that was flexible enough to create unlimited context/project lists.  I’d want a "master view" of next actions with options to filter by date, priority, etc, as well as a list-specific view of next actions.  I’d want an overrideable option to sync with Outlook.  It would have to play nicely with DateBk 5 and other similar apps (Agendus, etc…).

What else?  Right now, everything is fair game.  Drop your ideas into the comments…