I'm using this and it works pretty well once I adapted it to my needs.
Note - When I upgraded to ESRI 2, SL4 & VS2010 I had some issues with Dictionary & IDictionary in the GPX sections. It might just be me and my environment.
I don't think they have a sample there unfortunately. But you can download the project and run it on your local computer. This is what I did to learn about this functionality.