This plugin for ActiveRecord makes the "ID" field into a URL-safe GUID It is a mashup by Andy Singleton <andy@assembla.com> that includes * the UUID class from Bob Aman. * the plugin skeleton from Demetrius Nunes * the 22 character URL-safe format from Andy Singleton You can get standard 36 char UUID formats instead TODO: Auto-detect a character ID field and use a GUID in this case (DRY principle) It has been extended by Brian Morearty with: * the addition of a mysql_create function (configurable with a guid_generator accessor) for much better performance * id assignment is now done before_create instead of after_initialize, to more closely mimic the default Rails behavior of assigning an id upon save. This library is free software; you can redistribute it and/or modify it under the terms of the MIT license. TO USE Install as a plugin in the rails directory vendor/plugin/guid define ID as char(22) call "usesguid" in ActiveRecord class declaration, like class Mymodel < ActiveRecord::Base usesguid end if your ID field is not called "ID", call "usesguid :column =>'IdColumnName' " If you use MySQL as your database, you can make guid generation much faster by putting this in config/environment.rb: ActiveRecord::Base.guid_generator = :mysql