By Ian Sherr

Just in time for the holidays, Apple is offering a new, or at least new-ish, product.

On Monday, the Cupertino, Calif.-based released an update to the software that runs its many mobile devices. The update, dubbed iOS 4.2, allows iPad users to read emails from multiple accounts, connect with one another using a game-themed social network and wirelessly stream music to their stereos.

In particular, the new features target Apple’s popular iPad, which hasn’t been able to perform many of the same functions of its siblings, the iPhone and the iPod Touch. The changes for the iPad are so great, says Apple Chief Executive Steve Jobs, they revolutionize a product he has already declared “revolutionary.”

“iOS 4.2 makes the iPad a completely new product,” Jobs said in a press release announcing the upgrade, even though iPads look exactly the same and come in their six original configurations.

The new system does give the iPad, already the standard bearer for tablet computers, some nifty new functions. The iPad can now run multiple applications at the same time, something the iPhone and iPod Touch have been able to do since June. For example, users can stream Pandora radio stations while surfing the web or reading a book on Amazon.com’s Kindle app.

The iPad’s email program has also been revamped. It now allows users to gather email from any account they have in a single inbox. That lets users maintain separate accounts for separate purposes, but read them all in one place.

Users will also have an easier time organizing their applications on the iPad. To the date, iPad users have had to let their apps sprawl across the device’s home screen, which serves as the device’s desktop. Now, a folder function will allow neat freaks to group related apps.

Apple has also made its “Find My iPhone” service free. The feature, which until recently was only available through Apple’s $99 per year MobileMe subscription service, helps iPad, iPhone 4 and some iPod Touch owners locate their gadgets should they misplace them.

Owners of the iPhone and iPod Touch are also getting new wireless features, dubbed AirPlay and AirPrint. As the names imply, AirPlay allows users to stream music, movies and photos to other devices, such as an Apple TV or a wireless speaker system, while AirPrint can push documents through the air to a compatible printer.

The software update lets most of Apple’s mobile devices do the same things. They also can’t do the same things. Like, wirelessly synchronize photos and music with iTunes. Or act as attachable USB drives, like older iPods could.

Maybe those features will be introduced for the next holiday shopping season.