Hamburg - Laptop buyers should pay special attention to the amount of RAM installed in the computer. Two gigabytes (GB) is the rock-bottom threshold, recommends Hamburg-based Computerbild magazine, as that is enough to work with Windows Vista.

Those who must satisfy "memory hungry" applications like photo editors are best advised to go for a model with 3 GB of RAM. The magazine tested eight current laptops costing around 500 dollars each.

Oslo - A Norwegian search service has launched the site Kvasir Junior (http://www.kvasir.no/jr/) which targets children aged six to 12 who want to explore the internet.

The aim is to give children a safe option and focuses on learning, information and entertainment.

"The internet offers great opportunities for children and youths, but also contains dangers," Ingrid Stover Jensen of Kvasir said in a statement.

The criteria for sites that can be registered on Kvasir Junior include "varied content" and even if the sites are geared towards adults, they can be accessed by older children if the language and quality is acceptable.

The sites also have to be up and running, and easy to use.

San Francisco - Apple has expanded its iPod lineup in time for the Christmas season with flatter, more colourful models and even more features.

Steve Jobs, Apple's chief executive, rolled out the fourth generation iPod nano and a retooled iPod touch recently. He also presented a new music software platform dubbed Genius, designed to help users compile playlists.

Frankfurt - Relaxing on the couch and browsing through a weighty tome - for many, that sounds like paradise. Trying to drag that book along in your pocket to be read on the train or bus is less fun, though. Digital alternatives to printed books or e-books have been available for a while. But until now they've only enjoyed a niche existence. That might be about to change.

"Reading devices developed especially for e-books should provide a pleasant reading experience," says Gudrun Bolduan from the German Publishers & Booksellers Association. The problem: only a few of the devices have been widely available to date, and with prices of around 500 dollars, they were anything but cheap.

Moscow  - President Dmitry Medvedev has announced a comprehensive modernization of Russia's armed forces and its nuclear weapons, Russian media reported Saturday.

By 2020, there would be complete overhaul of the nuclear deterrent, Medvedev said at the conclusion of military exercises in the Urals.

The plans include a new generation of nuclear submarines and cruise missiles, as well as better coordination of the country's missile defence system with reconnaissance satellites in space.

Beijing  - China's first spacewalk got under way Saturday as astronaut Zhai Zhigang slipped out of the Shenzhou VII spacecraft and said, "I feel well."

Zhai, the commander of the three-man mission, waved to cameras broadcasting the event live in China as he left the craft's orbital module at 4:39 pm (0839 GMT).

"I am here greeting the Chinese people and people of the whole world," the astronaut told mission control in Beijing.