<%= link_to 'Confirm my account', confirmation_url(@resource, :confirmation_token => @resource.confirmation_token, :redirect_to => stored_location_for(@resource)) %>

def show
  if params[:redirect_to]
    session["user_return_to"] = params[:redirect_to]
  end
  super

end

def stored_location_for(resource_or_scope)
   scope = Devise::Mapping.find_scope!(resource_or_scope)
   session.delete("#{scope}_return_to")
end

class Users::ConfirmationsController < Devise::ConfirmationsController
     before_filter :set_redirect_location, :only => :show

     def set_redirect_location
         session["user_return_to"] = params[:redirect_to] if params[:redirect_to]
     end
end

devise_for :users,
           :controllers => { :confirmations => 'users/confirmations'}

class User < ActiveRecord::Base
  …
  attr_accessor :return_to
  …
end

class RegistrationsController < Devise::RegistrationsController
  def create
    params[:user][:return_to] = session[:user_return_to] if session[:user_return_to]
    …
    super
  end
end

<% if @resource.return_to %>
  <%= link_to 'Confirm my account', confirmation_url(@resource, :confirmation_token => @resource.confirmation_token, :redirect_to => @resource.return_to) %>
<% else %>
  <%= link_to 'Confirm my account', confirmation_url(@resource, :confirmation_token => @resource.confirmation_token) %>
<% end %>

class ConfirmationsController < Devise::ConfirmationsController
  before_filter :set_redirect_location, :only => :show

  def set_redirect_location
    session[:user_return_to] = params[:redirect_to] if params[:redirect_to]
  end
end

class ConfirmationsController < Devise::ConfirmationsController
  def create
    self.resource = resource_class.send_confirmation_instructions(params[resource_name],session[:user_return_to])

    if resource.errors.empty?
      set_flash_message(:notice, :send_instructions) if is_navigational_format?
      respond_with resource, :location => after_resending_confirmation_instructions_path_for(resource_name)
    else
      respond_with_navigational(resource){ render_with_scope :new }
    end
  end
end

class User < ActiveRecord::Base
  def self.send_confirmation_instructions(attributes={},redirect=nil)
    confirmable = find_or_initialize_with_errors(confirmation_keys, attributes, :not_found)
    confirmable.return_to = redirect if confirmable.persisted?
    confirmable.resend_confirmation_token if confirmable.persisted?
    confirmable
  end
end