#!/usr/bin/ruby

require 'uri'
require 'net/http'

# Output YouTube ID's, one per line from a URL.
url = 'http://www.youtube.com/'
res = Net::HTTP.get_response( URI.parse( url ) )
reg = /href="\/watch\?v=([^"|^&]*)/

matches = res.body.scan( reg )
matches.uniq! 
puts matches