Clarke A. Wixon ("Quicksand") is a U.S. (California) intellectual property attorney by day, OpenMoko hacker by night.
I hope to bring some useful PDA-style applications to the OpenMoko platform, either by porting existing desktop applications, by fine-tuning existing bitbake recipes and user interface definitions in the OpenEmbedded database to better take advantage of the OpenMoko form factor and capabilities, or by coding something up to fit my own personal needs.
I have a degree in mathematics, and I have interests in natural language processing and in electronic music. Accordingly, as time permits, I have some ideas for a free-form handwriting recognition engine for Linux that I would like to at least prototype (the currently available options, for example as in the Nokia 770/800, are proprietary). And I'd love to have a simple softsynth and sequencer combination available on the Neo for sketching out musical ideas while traveling.
My intellectual property law practice is online at wixonlaw.com 
Free42 is an excellent GPL2 RPN calculator by Thomas Okken modeled after the HP42 series of calculators. I have been using it for several years on my VGA PocketPC, and before that on a PalmOS device.
Unfortunately, there was no bitbake recipe for it in the OE database, so I had to make one. This being my first attempt at such, it might be a bit of an ugly hack, but it works! And it runs beautifully on the Neo.
I have submitted this to the OE people upstream for inclusion into their metadata package. For the impatient, the .bb recipe and patches are available via their bugtracker. 
Xournal  is a very nice scribble-notes package inspired by the Microsoft Journal application provided with Tablet PC versions of Windows. It uses a vector-based ink model and supports multi-colored ink, different kinds of erasers, highlighters, and (in the new version) typed text. It runs very well on the desktop, and marginally well on the Neo at this time, but with some fine-tuning and user-interface consolidation I think it will be a very useful addition to our suite of applications. I will be working on it in the coming days.
Notecase  is a hierarchical text note manager with rich text formatting capabilities. It already runs well on the Linux desktop, the Windows desktop, and on the linux-based Zauruses. There's a .bb recipe for an old version of Notecase in the OE metadata, and in the coming days I will be bringing that up to date and tweaking the user interface for small-screen devices such as the Neo.
Password Safe - Unless someone beats me to it, I would like to implement or port an encrypted password safe for the Neo, preferably one that is able to exchange data with both a Linux desktop application and a Windows desktop application. A good candidate for this would be KeePass and KeePassX but I need to investigate alternatives.
Handwriting Recognition - Handwriting recognition does pretty well these days, both on the Windows platform (XP Tablet PC Edition and Vista), and on Mac OSX (Inkwell, I believe it is called, which is based on work originally done for the Newton). Even Microsoft PocketPC platform has reasonably good recognition (through the Calligrapher third-party application, which Microsoft has licensed in an older version as the Transcriber built into Windows Mobile).
The Nokia 770/800 apparently has a handwriting recognition engine that is proprietary, without source available.
I would love to see a free handwriting recognition engine that is unencumbered by commercial license restrictions and patents, and can be used with OpenMoko. With my background in mathematics and natural language processing (which I had the privilege to work on at Xerox PARC some years ago), I have some ideas on how to go about this in a relatively "processor-light" manner.
This will be a spare-time project at best, so it might not see the light of day for quite a while.
Music Platform - I had a General Midi sound generator that attached to my ancient Palm Vx, and a rudimentary step sequencer to go with it. It was polyphonic and multitimbral, but it wasn't really useful for anything more than skething out ideas because of the constraints of the old PalmOS 3.x user interface. But it was a load of fun, and useful within its constraints, so I would love to see something like this available in the OpenMoko project.
This is another project that might take a long while to come to fruition, but it is one I have had in mind for a while.