I ran across GeoRuby, a Ruby gem for handling spatial data types in a database, awhile ago. However, I never sunk my teeth into how it worked and how to get it going.
In the meantime, I settled myself to using the adequate Cartographer Plugin to easily create Google Maps. I even went so far as to extend Cartographer to switch to Yahoo! maps and MapQuest Maps.
I just came across another mapping gem, YM4R (yellow maps for Ruby) which handles GoogleMaps v2 (there is a patch for Cartographer to do the same), and Yahoo! maps, local, and traffic. Wow!
Not only that, it's by the same developer of GeoRuby, The Pochi Superstar Mega Show!.
Check out the very good, and complete Ym4r + GeoRuby + Spatial Adapter tutorial