Update: I've now written a simple GPX track logger for Windows which can be downloaded at http://maps.kcip.com
I've been involved in the IT industry for over 10 years, but with no connection to mapping or geodata, though I've been making maps as a hobby since I was about 8 years old.
I've written quite a bit of PC (Windows) mapping software over the years for my own use, but have never been able to distribute this in the (open source) way I'd prefer due to lack of free maps. In fact the lack of affordable maaping data has stopped me releasing any code at all. I suspect many people are in the same position. I also ended up using OSGB36 as a datum, ugg.
I'm hoping to rewrite some of this code when I get a chance. The only current issue is licencing, as any code I release would be under a BSD style licence (to allow mashups with commercial code and data) and so would have to be separate from the Openstreetmap data and its sharealike licence.
I'm also a radio amateur (M1JRC) and one of my interests is the use of mapping data for APRS, radio direction finding and locating sources of interference.
I've very interested in the global nature of projects such as Openstreetmap. I visited Zimbabwe in 2001 with a GPS unit and was unable to find any electronic mapping (as I write - October 2006, Google still has no street data for Zimbabwe) and only one paper map (the Mobil Harare road atlas) with no way to reference this to WGS84 waypoints! I believe community mapping projects could be a really useful contribution to such places.