Log the IP address used to create an account.

app/controllers/user_controller.rb

@@ -16,6 +16,7 @@ class UserController < ApplicationController
     @user.visible = true
     @user.data_public = true
     @user.description = "" if @user.description.nil?
+    @user.creation_ip = request.remote_ip
 
     if @user.save
       flash[:notice] = "User was successfully created. Check your email for a confirmation note, and you\'ll be mapping in no time :-)<br>Please note that you won't be able to login until you've received and confirmed your email address."

db/migrate/016_add_creation_ip.rb

@@ -0,0 +1,9 @@
+class AddCreationIp < ActiveRecord::Migration
+  def self.up
+    add_column "users", "creation_ip", :string
+  end
+
+  def self.down
+    remove_column "users", "creation_ip"
+  end
+end