Last year in February Engadget reported that Sweden's UI design company The Astonishing Tribe (TAT) showcased a dual-screen UI concept, stating that in future devices could sport such a setup.

A year later Kyocera Communications has launched a dual-screen Android phone called Echo on Sprint network; however TAT was acquired by BlackBerry maker RIM in December 2010.

Dual-screen form factor has found significant use on desktops and even tablets. Recently Kno a giant dual-screen tablet was released at the CES 2011. Kno sports two 14-inch screens with a screen resolution of 1440x900 and has a special stylus which helps in taking notes. It is powered by an Nvidia Tegra 2 processor and runs on a Linux based UI. However the tablet weighs 5.6 pounds and is targeted at students. An Apple iPad weighs a mere 1.6 pounds.

However questions regarding the usability of a dual-screen phone galore. The Kyocera Echo offers two 3.5-inch displays with 800x480 resolutions. Each screen can run a different app like an email can be opened on one screen and a browser on the other. It also offers the option of combining the screens and it turns into a 4.7-inch display.

The downside of such an arrangement is that the phone needs a powerful processor. Echo runs on a Snapdragon 1 GHz processor which is not dual-core and thus it drains the battery life. A limitation which Kyocera has acknowledged as it offers a spare 1370mAh battery with a charging cradle. The cradle can also tether the spare battery to Echo as an external power supply.

The weight of the smartphone has not been revealed although it is .67 inches thick compared to iPhone 4 which is .37 inches thick and weighs 4.8 ounces.

The phone uses a pivot-hinge which allows using the display in different formats. However only dedicated apps built with Kyocera APIs are currently functional on each screen individually. However a SDK for apps is coming but for now third-party apps are not functional on individual screens.

The key benefit that a dual-screen phone offers is multi-tasking; allowing a user to access two apps on different screens thus a user can also send a text message and watch a video simultaneously. It also offers the flexibility to turn it into a larger screen for multimedia content once the screens are used in conjunction.

The dual-screen phone can give a tough fight to QWERTY keypad phones, as the space used up the sliding keypad can now be used for an additional screen. Also the additional screen could be used as a virtual QWERTY keypad.

A flipside to the dual-screen Echo is that it does not offer a front-facing camera for video chat, a feature which could have been optimized on a two-screen form. Also the phone is currently 3G-only and does not run on WiMAX which leaves a multi-media augmented phone in want of speed. Another missing facet is 3D capability which would have made the device an excellent fit for 3D games.

While the possibilities on the phone are multiple, Kyocera and Sprint would have to address issues like more processing power, better battery life and more apps that could be featured on the phone.

The Kyocera Echo runs Android 2.2 powered by a Snapdragon 1GHz chip, sports 1GB internal memory with an 8GB microSD card and support for 32 GB. It has 5 MP camera with 720p video capture capacity and is priced at $199.