Working a project this weekend I decided to check what options where out there and stumbled upon google_maps plugin by bhedana on GitHub. In a few minutes I had it installed and rendering maps without any of the pain in setting up maps manually. This plug-in gives you moderate control of the map. You can customize controls, center, zoom, add custom markers and plot polyline routes.
If you are doing anything with plotting points on a Google Map in Ruby on Rails you should look at this plugin-in. If you have a better plug-in for maps please let us know.