Apple launched iOS 4.2.1 for the iPhone, iPod touch, and iPad today. It’s available for download today — just connect your mobile device to your computer and launch iTunes. If you don’t get an update notice, select your mobile device from iTunes and click the Update button to check for the latest software update.

While the update brings a number of new features to iPhone and iPod touch users, the big news is iPad support. This is the first version of iOS 4.x that will run on the iPad, which means that iPad users will finally be able to multitask, group apps into folders, change the home screen background, and perform other actions that have been available on smaller devices for months. It also means that Game Center will be available for the iPad.

Apple is also bringing AirPlay technology to all three devices, allowing users to stream music, videos, and photos from an iPhone, iPod touch, or iPad to an AppleTV.

As we’d been hearing, it looks like AirPrint functionality will be available — but it will only allow you to send print jobs from iOS to a supported WiFi-enabled printer including several recent models from HP. The press release doesn’t make any mention of sending print jobs to your Windows or Mac PC to pass along to a connected printer.

In a surprise announcement, Apple has also removed the Find My iPhone feature from the subscription-based MobileMe service. Users can now find missing devices from the web by installing the free Find My iPhone app on and iPhone, iPod touch, or iPad. The app will help show where your mobile device is on a web-based map, and it will also let you display a message or play a sound on your phone.

The OS update also adds support for TV program rentals.

Apple says iOS 4.2 will work with the iPad, iPhone 3G and newer services, second, third, and fourth generation iPod touch models. Multitasking and some other features will only work on the iPhond 3GS and up and the 3rd generation iPod touch or newer. Find My iPhone is only available on the latest devices including the iPad, newest iPod touch, and the iPhone 4.

Brad Linder

Brad Linder is editor of Liliputing and Mobiputing.He's been tinkering with mobile tech for decades and writing about it since...