I've been getting lots of email around the contribution I made back about a year ago to OpenNetCF (v1.4), see www.OpenNetCF.org
This was back in the day when the Compact Framework 2.0 had just been launched and we finally had access to serial ports without the need to P/Invoke.
I put together at least a starter for ten set of classes that would extract data from the stream of NMEA sentences and fire corresponding events, i.e fire an event when position changes or a satellite appears in view.
Of course this hasn't been a solo-mission, once the GPS library was put up as shared source I had loads of input into how the library should work. It was amazing to see people rolling their sleeves up and helping me when my basic maths skills ran out of steam (that happened fairly early on 
)
When the Windows Mobile 5 SDK shipped we saw the release of the GPS native classes. This superceded the OpenNetCF library and provided a much more robust implementation of the GPS code. To get a sample application that utilises these Windows Mobile 5 features have a look at -
http://msdn2.microsoft.com/en-us/library/ms879577.aspx
Peter Foot found a couple of little issues with the sample that he blogged about at -
http://www.peterfoot.net/FixingTheWindowsMobile50GPSSampleCode.aspx
However it seems that OpenNetCF GPS library is still out there and being used. I was amazed to see a screenshot of it being used as one of the first apps on a Gumstix device running CE. * Note the UI was not added by me, another OpenNet contributor (who's name escapes me), did a superb job of putting a face on the library code.
http://66.102.9.104/search?q=cache:oo4LpaT5eaUJ:home.tampabay.rr.com/vescovi/gumstix/gumstix.htm+gumstix+gps+ce+opennetcf&hl=en&ct=clnk&cd=3&gl=uk
So although happy to take questions about my early attempt to provide a generic open source GPS library, I think the native code stuff in WIndows Mobile 5 now wins.
For those of you, still out there wanting features and add ons to the OpenNetCF offering maybe with enough demand I'll do a version 2, taking the best of what's provided in Windows Mobile 5 and adding on a few of the bells and whistles that have evolved with the OpenNetCF version.