I recently [re]discovered the years and years of accumulated GPS logs that I had from dragging my GPS with me on every hike or drive and decided to do something with them. After some Perl scripting and ImageMagick processing, I got this:
Click on the picture above for a full size view of this and other images.
BTW, this is my first diary entry - I hope the HTML works... If not, the URL is this: http://avtanski.net/projects/gps. The track visualization video is here: http://www.vimeo.com/23697355