lib/foursquare2/lists.rb
def add_list_item(list_id, options={})
      response = connection.post do |req|
        req.url "lists/#{list_id}/additem", options
      end
        return_error_or_body(response, response.body.response.item)
    end
def add_list_item(list_id, options={})
      response = connection.post do |req|
        req.url "lists/#{list_id}/additem", options
      end
        return_error_or_body(response, response.body.response.item)
    end
Add an item to a list: https://developer.foursquare.com/docs/lists/additem

 @param [String] list_id - The id of the list to update
 @param [Hash] options (all optional)
 @option options String :venueId - A venue to add to the list.
 @option options String :text - text to add to item
 @option options String :url - associate a url with the tip
 @option options String :tipId - Used to add a tip to a list
 @option options String :listId - Used with itemId to copy item from a list
 @option options String :itemId - Used with listId to copy item from a list