jetable.org is a great service to generate a temporary email which you can use to signup and avoid spam. Run this script from your CLI to have an email generated for you, using jetable.org service.

jetable.rb

require 'rubygems'
require 'mechanize'
require 'resolv'

# check if first argument exists
if ARGV.length == 0
  abort "ERROR: First argument must be your email\n"
end

EMAIL = ARGV[0]
URL = "http://www.jetable.org/en/index"

def validate_email_domain(email)
	domain = email.match(/\@(.+)/)[1]
	Resolv::DNS.open do |dns|
		@mx = dns.getresources(domain, Resolv::DNS::Resource::IN::MX)
	end
	@mx.size > 0 ? true : false
end

# check if email is valid
if validate_email_domain(ARGV[0]) == false
	arbort "ERROR: Email not valid"
end

agent = Mechanize.new { | agent |
	agent.user_agent_alias = 'Mac Safari'
}

# Get the start page
start_page = agent.get(URL)
start_form = start_page.forms.first
start_form.email = EMAIL
available_times = start_form.field_with(:name => 'time').options
start_form.time = available_times.first
confirm_page = start_form.submit

puts "All done, check you email for confirmation"