The next release of the Apple mobile operating system iOS 4.2 promises to bring the ability to print documents, emails, photos and more from suitably equipped iPads and iPhones. Printing from the iPhone has been a much-missed feature to date and Apple appear to have accepted the need for it. Or have they?

As with any new iPhone operating system release, Apple appear to have given with one hand and taken with the other. The headline grabbing print function, called AirPrint, is not all encompassing as initially suggested thanks to a list of prerequisites which will exclude many iOS users.

To print from your iPad running the shiny new iOS 4.2 you will need at the very least an HP ePrint printer (currently there are only three, the B210, the C310 and the C410). Failing that, any printer can be used. As long as the print job is sent to the printer via a Mac running OS X 10.6.5 (which is still in beta testing).

As always, these new features will be unavailable on older hardware such as the iPhone 3G, iPhone 2G and the second generation iPod Touch.