This sounds fairly similar to Riak, but apparently sells for $30,000/node o_O: http://www.clustrix.com/
You can add location information to your Tweets, such as your city or precise location, from the web and via third-party applications. You always have the option to delete your Tweet location history. Learn more
This sounds fairly similar to Riak, but apparently sells for $30,000/node o_O: http://www.clustrix.com/