AirPrint without WiFi Access Point

If you have an AirPrint enabled printer and an iPhone/iPad running iOS4.2 or above you can print directly to the printer without the need for both devices to be connected through the same WiFi access point. On your iOS device, go to your WiFi settings and in the list of networks you should see an entry that relates to the printer (so long as you are in range), and hey presto it all works

http://www.flexicoder.com/blog/index.php/2011/02/airprint-direct-to-the-printer/