Apple did not release AirPrint support in Mac OS X, which means you can’t print from your iPhone, iPad and other iOS devices to a shared printer connected to your Mac. Thanks to third party developers, you can install tools and hacks not directly from Apple to enable such function.
AirPrint Activator 2.0 is the best tool we found so far, and it is easy to install and use. Simply download the app from the developer’s site, run the app, and toggle the switch to ON.
That’s it. The app needs to be running in order for your iOS devices to detect the printer and to send jobs to the printer. Please note that AirPrint is available on iOS 4.2 and above.
If you can not find your printer in the AirPrint Activator, visit the System Preferences->Print&Fax screen to make sure you are sharing the printer.
We suspect Apple will be adding AirPrint support in Mac OS X Lion, the next major update due this summer. Until then AirPrint Activator is as good as it gets. AirPrint Activator 2.0 website contains download link, detail instruction and even a video guide. The app is free but please visit the donate link on the site if you can afford it.