simple-address-generator

https://github.com/designium/simple-address-generator

simple-address-generator allows you to create a complete Address model with fields and two main plugins that geocode address into coordinates and a Google Maps view with custom makers. To use, just add this gem to your Gemfile and then in your Rails 3 application, run: rails g simple_address_generator. Then run rails s and see in your browser http://localhost:3000/addresses.