The web mapping application "Mappetizer Travel Diary" which uses OSM as a background layer, now includes an overview map and also the possibility to implement a slideshow. Please have a look at it:

http://www.uismedia.de/mappetizer/traveldiary/TravelDiary_Ruth/index.html

The application bases on open standards like SVG and XML and doesn't need any web server technology. You have full access on your GPX-files, they are not uploaded somewhere else on a web server (like with all the Google applications).

So if you like my example, please feel free to try it with your own GPS data, and I am sure you have a lot of them ;-).
Download a demo copy from our homepage:
http://www.mappetizer.de/traveldiary/index.html

Any comments and suggestions are welcome.
-- Ruth