follow_members_of_twitter_list.rb

require 'rubygems'
require 'yaml'
require 'json'
require 'rest_client'

@config = YAML.load_file 'twitter_login.yml'
#twitter_login.yml looks like
#:user: username
#:password: password
@twitter = RestClient::Resource.new('http://twitter.com',@config)
@twitter_api = RestClient::Resource.new('http://api.twitter.com',@config)

def list_members user,list
  JSON.parse(@twitter_api["1/#{user}/#{list}/members.json"].get)['users']
end


list_members(<owner of list goes here>,<name of list goes here>).each do |member|
  @twitter["friendships/create/#{member['id']}.json"].post ''
end