Geo::Google::StaticMaps, which basically just transforms a map definition given as a bunch of nested hashes and arrays into a Static Maps API URL. It ought to support everything that the Static Maps API itself currently supports.
Google has added one of the most popular features of its consumer Google Maps product to the Google Maps API. Predictive travel time is oft-used by consumers to find best routes, and avoid traffic. Now, developers have access to the feature and can integrate the functionality into third party apps.