As powerful and multi-functional as smartphones have become, Motorola is looking to go one step further with its ATRIX 4G. Powered by a Tegra dual-core processor with each core running at 1 GHz to deliver up to 2 GHz of processing power and 1 GB of RAM, the device is designed to act as the brains of a computer that can be taken with you. In addition to being what Motorola calls the “world’s most powerful smartphone,” the ATRIX 4G is also designed to slot into external docks that turn the device into the engine for a desktop or laptop PC.

The Android 2.2 powered device runs Motorola’s Webtop application – a windowed UI that runs a full Firefox 3.6 browser with support for Flash 10.1 and provides multi-tasking capabilities. Users can run Android applications in a window, send instant messages and make phone calls, all at the same time. The device also comes with an integrated Citrix Receiver application to provide secure access to virtual desktops as well as Windows, web and office applications hosted on Citrix XenDesktop.

At CES 2011, Motorola was demonstrating the ATRIX 4G being used with the HD Multimedia Dock and the Laptop Dock. The phone connects to the docks via its mini USB and mini HDMI ports. The HD Multimedia Dock then provides three USB ports and an HDMI port, so it can be connected to a monitor or HDTV, and USB input devices such as a keyboard and mouse. There’s also a remote for controlling multimedia content from the couch when using the device’s Entertainment Center application.

Meanwhile, the Laptop Dock features an 11.6-inch screen, full keyboard, trackpad, two USB ports, and stereo speakers and provides up to eight hours of battery life. Weighing in at 2.6 lb (1.17 kg), the ATRIX 4G slots into the back left of the device behind the display to give users a laptop form factor that leverages the power of the phone.

When users undock the phone, it retains the state of the Webtop app between sessions so when it is plugged back in – even to a different dock – the previous session is automatically restored. The content is also available when the phone is undocked, so if you didn’t finish reading a web page on your monitor before you had to head out the door, you can pick up where you left off on the train on the way to work.

For the times when you’re using the phone without a dock you’re unlikely to be too disappointed thanks to a qHD (960 x 540) 4-inch display with 24-bit color graphics. Other specs include up to 48 GB of storage (16 GB built-in and up to 32 GB via MicroSD card), 2.4 GHz and 5GHz 802.11n Wi-Fi, Bluetooth 2.1+EDR, VGA front and 5-megapixel rear facing camera with LED flash, built-in fingerprint scanner, and 1930 mAh battery to provide up to nine hours of talk time and up to 10.4 days on standby. There’s also support for AT&T’s Mobile Hotspot service for connecting up to five additional Wi-Fi enabled devices.

The Motorola ATRIX 4G measures 2.5 x 4.6 x 0.4 inches (6.35 x 11.6 x 1 cm) and weighs 4.8 oz (136 g). In the U.S. it will be available exclusively through AT&T in Q1 2011.