Nokia took the stage on Day 1 of Mobile World Congress to announce two new business-focused handsets, the super-thin E55 and the sliding E75.Nokia knows how to make stylish, attractive phones. It built on the benchmark set by its popular E71 smartphone and has crafted two brand-new E series devices in its image.

The E55 is, according to Nokia, the thinnest smartphone in the world. It has a 20-key SureType style keypad (similar to a BlackBerry Pearl) with two letters per key. This helped Nokia make it smaller. It also comes with a full set of messaging software and all the specs you'd wish to see on a smartphone, including GPS, 3G, Bluetooth and Wi-Fi.

The E75 merges the function of the Communicator Series with the style of the new E series design language. It is a sideways slider that reveals a full QWERTY keyboard when open, and it has a regular 12-key number pad when closed.

Both phones will be loaded with Nokia's new messaging software, and will have 3.2-megapixel cameras with flash and video capture.

The E75 will be available in March and the E55 will be available in the second quarter.