I use this on about all of my projects, a really great way to cleanup hashes. Especially useful for hashes loaded from yaml.

recursive_symbolize_keys.rb

class Hash
  def symbolize_keys
    inject({}) do |options, (key, value)|
      options[(key.to_sym rescue key) || key] = value
      options
    end
  end
  def recursive_symbolize_keys
    inject({}){|result, (key, value)|
      new_key = case key
                when String then key.to_sym
                else key
                end
      new_value = case value
                  when Hash then value.recursive_symbolize_keys
                  when Array then value.recursive_symbolize_keys
                  else value
                  end
      result[new_key] = new_value
      result
    }
  end
end

class Array
  def recursive_symbolize_keys
    inject([]){|result, value|
      result << case value
      when Hash then value.recursive_symbolize_keys
      when Array then value.recursive_symbolize_keys
      else value
      end
      result
    }
  end 
end