## view, new.rhtml

<%= start_form_tag :action => 'create'%>
<%= error_messages_for 'user' %>

<p>Screen Name: <%= text_field 'user', 'screen_name' %></p>
<p>Email Address: <%= text_field 'email', 'email' %>
<p>Password: <%= password_field 'user', 'password', :size => 10 %></p>
<p>Confirm Password: <input type="password" name="user[confirm_password]" id ="user_confirm_password" size="10"></p>
<p>Zip Code: <%= text_field 'user', 'zip_code', :size => 5, :maxlength => 5 %></p>
<%= submit_tag 'Create New User' %>
<%= end_form_tag %>

## model, users.rb

class User < ActiveRecord::Base
  validates_presence_of :screen_name

  has_many :emails
  has_many :logins

  attr_accessor :password, :confirm_password

  def validate
    errors.add(:password, "not the same") unless password == confirm_password
  end

  def before_save
    self.password_sha1 = Digest::SHA256.hexdigest(password) if password
  end

end

## controller, user_registration_controller.rb

class UserRegistrationController < ApplicationController

  verify :method => :post, :only => [ :destroy, :create, :update ],
         :redirect_to => { :action => :list }

  def new
    @user = User.new
    @email = Email.new
  end

  def create
    @user = User.new(params[:user])
    @user.emails << Email.new(params[:email])
    if @user.save
      flash[:notice] = "New user created successfully"
      redirect_to :action => 'whereever'
    else
      redirect_to :action => 'new'
    end
  end
end