Why buy a smartphone, tablet and netbook when you can combine all three in one device?

That's a question AsusTeK is hoping you'll ask, as the Taiwan-based company rolled out its innovative Padfone at the Mobile World Conference in Barcelona, Spain.

With a 4.3-inch Super AMOLED touchscreen for mobile use, you can slip the Padfone into the back of a 10-inch docking display that allows it to work like a tablet, then connect both devices to a docking keyboard for computer use and longer battery life.

Docking with the tablet extends the phone's 1520 mAh Lithium battery's life by five times, while adding the station dock extends battery operation nine times, Asus promises.

Asus notes in its promotional material that you can save money on data by using a single plan for a device with three uses. The device is set for an April launch, but the cost and carrier partners have not been announced.

Pushing the Envelope

Running Android's 4.0 operating system, also known as Ice Cream Sandwich, the Padfone has a Qualcomm Snapdragon S4 8260A dual-core 1.5-GHz processor and packs a rear 8-megapixel auto-focus flash f2.2 aperture, as well as a front megapixel VGA camera. It will come in 16-, 32- or 64-GB versions with a microSD slot for added storage.

The device is also similar to the Motorola Atrix, which has an available docking station, and goes one step beyond Samsung's Galaxy Note, which is a smartphone sized large enough to be used as a small tablet.

Consolidating a range of devices or making them adaptable for other uses is a simple matter for manufacturers, but don't expect to see them morph together the way printers, scanners, copiers and fax machines have any time soon.

"This is outside the trend," said analyst Gerry Purdy of MobileTrax. "Asus is trying to push the envelope, enabling phone and notebooks to occupy a single user experience. It has one CPU driving the phone in its core, the tablet in its dock and a full touchscreen with keyboard as a notebook."

Apple's iPad tablet can also be operated with a bluetooth-enabled keyboard, but the company is unlikely to take any steps toward consolidation since it has massively successful product lines for the iPhone, iPad and a line of Macbooks.

Slow Adoption Seen

That could create an opening for rivals who emphasize the cost-saving and convenience of devices like the Padfone. But Purdy said the first generation faces limitations.

"There are a lot of challenges in trying to replace a notebook [with a tablet]," he said. "An operating system like Android is not as functional as a desktop OS.

"A little bit of innovation will probably drive the market, but I don't think we're going to have disappearing tablets and laptops any time soon. The market is a little too new for wide adoption of this."

In addition to the Padfone, Asus also unveiled its Transfomer Pad Prime, Transformer Pad Infinity and Transformer Pad 300 series.