Hi
I have a site for trail information (in Swedish). I needed a light and simple GPX editor but I could not find one, so instead I wrote one. It’s an opensource project (but I have not had time to publish the code yet) which will be released under GPLv3. The editor is browser based and is written in Javascript. It can handle simple GPX editing right now.
Anyway, I have a simple version live on the site. But version 1.0 is soon ready to be released. In the mean time you can see some screenshots at http://twitter.com/opentrailmap (the feed is in Swedish but there are some screenshots at least there).
I just thought that someone here might think it was an interesting experiment.
Screenshot: http://twitpic.com/32q2x1/full