The Sidekick line's newest installment, the Android-running Sidekick 4G

The T-Mobile Sidekick, which recently got its data services put to rest for good, will be getting a second life as the Android-based Sidekick 4G.

The Sidekick 4G will be the first Sidekick to include a touchscreen, in this case a 3.5-inch display, but other than that, the looks stay true to the brand’s signature stylings: the same overall shape, the same 5-row QWERTY keyboard. The display slides out with a “pop-tilt” hinge (not the swiveling screen of old), and an optical trackball has been put in place of the old physical trackball.

Group Text and Cloud Text apps appear to be key features of the device, letting users send messages in a reply-all fashion while texting groups and friends from multiple devices, such as your laptop or desktop computer, in addition to the Sidekick.

“We’ve reinvented the messaging experience that made the Sidekick such an iconic device, and supercharged it with communication and entertainment experiences that take full advantage of our 4G network,” says Andrew Sherrard, T-Mobile’s senior vice president of product management.

The T-Mobile Sidekick is the phone that (arguably) started the smartphone revolution in 2002. Before the iPhone burst onto the scene, wowing us with its capacitive touch display and light, slender form, the Sidekick kept us connected with instant messaging through its signature spin-out display and QWERTY keyboard. It was an especially big hit among teens, whose texting habits primed them to see the value of a keyboard (and who were about as likely to use a BlackBerry as they were to wear a navy blue blazer).

Over the years the Sidekick got upgraded, and upgraded again, but it eventually lost out to a new breed of app-filled, touchscreen smartphones.

The Sidekick 4G built by Samsung is an attempt to make the iconic name competitive with today’s best smartphones. Accordingly, it’s got the obligatory 1-GHz processor (a Cortex A8 Hummingbird). It runs Android 2.2 Froyo, a respectably recent version of Google’s mobile operating system.

According to a T-Mobile statement, “Android continues to be a strategic bet for T-Mobile, and we’re expanding the current lineup to offer a robust messaging experience on a popular platform — at speeds as fast as your home broadband.”

The Sidekick will also act as a mobile hotspot for up to five devices, and it will connect with T-Mobile’s 4G network, wherever that is available.

Of course, 4G doesn’t mean what it used to. In this case, it refers to T-Mobile’s HSPA+ network, which the carrier claims will give you 5 to 10 Mbps of download bandwidth.

If you used to own a Sidekick, would you ditch your current phone for a 4G Android version? Sound off in the comments.

Sidekick 4G [T-Mobile via MobileCrunch and Android Community]