In the spirit of "Release Early, Release Often", I want to provide my  
Google Maps Hacks files and see if anybody can do anything  
interesting with them:

http://rubyforge.org/cgi-bin/viewcvs.cgi/googlemapshacks/? 
cvsroot=googlemapshacks

I wanted to do this so I could create my own custom highlighted  
routes on maps.  Google Maps is great, but although it marks major  
roads, it doesn't mark bike routes.  I have other maps that show that  
info, but Google Maps is much more convenient sometimes.  What I  
wanted was a way to mark the bike routes on a Google map.

So, here's what I have.  I can create an XML file that contains a  
"polyline" element.  This draws a blue line on the map like the one  
you can get when you ask for directions.  The process for getting the  
line on the map is horribly convoluted, but it works, and the  
coordinate encoding system seems to work pretty well too.  I'm hoping  
that maybe someone else will feel inspired by this and want to make  
the process much more useful.

The files in CVS are in a pretty well commented, pretty useful  
state.  Like I said, the process is awful now, but pretty well  
documented in the comments for coords.rb.

Enjoy!

Ben