gistfile1.txt

def self.symbolize_keys(hash)
  hash.inject({}){|result, (key, value)|
    new_key = case key
              when String then key.to_sym
              else key
              end
    new_value = case value
                when Hash then symbolize_keys(value)
                when Array then value.map{ |v| v.is_a?(Hash) ? symbolize_keys(v) : v }
                else value
                end
    result[new_key] = new_value
    result
  }
end

Breadcrumb: http://devblog.avdi.org/2009/07/14/recursively-symbolize-keys/