You can get iPhone push notifications from lots of online services, but what if you want something from your home to send you alerts? Learn how to get iPhone push notifications when your letter carrier delivers your mail with this Arduino project. No matter where you are, you’ll be the first to know when the latest volume of MAKE magazine is delivered!

More information about this project (including the code) can be found here: http://blog.makezine.com/archive/2010/12/snail_mail_push_alerts.html