gistfile1.builder

#!/usr/bin/env ruby
require 'net/http'

def validate(url)
    uri = URI.parse(url)
    response = Net::HTTP.get_response(uri)
    
    case response
    when Net::HTTPSuccess
      return uri
    when Net::HTTPRedirection
      return 'redirected: '+response['location']
    else
      return nil
    end
end

#puts validate('http://germanforblack.com') # redirects
puts validate('http://germanforblack.com') # doesn't redirect

Ah, yea, that second URL was meant to read http://www.germanforblack.com.
I knew your site was using www redirection, so it popped into my head as a test case.