Use this shell-script to change your DNS servers to the European Unblock-US servers via one simple command. Requires the 'open4' gem.

unblock.rb

#!/usr/bin/env ruby

begin
  require 'rubygems' if RUBY_VERSION =~ /^1\.8/
  require 'open4'
rescue LoadError
  puts "Please install the `open4` gem"
  exit 1
end

# Get the primary service ID
status = Open4::popen4("scutil") do |pid, stdin, stdout, stderr|
  stdin.puts "open"
  stdin.puts "get State:/Network/Global/IPv4"
  stdin.puts "d.show"
  stdin.puts "quit"
  stdin.close

  @@primary_service_id = stdout.read.match(/PrimaryService : ([\dA-F-]+)/)[1]
end

# Set the DNS servers for the primary service ID
status = Open4::popen4("sudo scutil") do |pid, stdin, stdout, stderr|
  stdin.puts "open"
  stdin.puts "d.init"
  stdin.puts "d.add ServerAddresses * 109.123.80.171 62.75.155.146"
  stdin.puts "set State:/Network/Service/#{@@primary_service_id}/DNS"
  stdin.puts "quit"
  stdin.close
end

# List the current nameservers
status = Open4::popen4("scutil") do |pid, stdin, stdout, stderr|
  stdin.puts "open"
  stdin.puts "get State:/Network/Service/#{@@primary_service_id}/DNS"
  stdin.puts "d.show"
  stdin.puts "quit"
  stdin.close

  dictionary = stdout.read
  puts "The current nameservers are: %s and %s" % [
    dictionary.match(/0 : ([\d\.]+)/)[1],
    dictionary.match(/1 : ([\d\.]+)/)[1]
  ]
end

system 'open http://check.unblock-us.com/'