Laptop users who need power on the go should check out the powergorilla and solargorilla from PowerTraveller.

The powergorilla, which is a high density lithium polymer rechargeable battery, will give users an additional 2-6 hours of power for their laptops.

It is claimed to be robust enough for travel and weighs 631g.

And, most importantly, you can use it to power your notebook and recharge other digital devices at the same time.

It comes with a worldwide AC adaptor which works in over 150
countries and has interchangeable heads for UK, US/Japan/China, Australia and Europe.

The powergorilla is compatible with most notebooks, iPods, iPhones, PDAs, MP3/MP4 players, handheld games consoles, satnavs, Nokia, Mini Nokia, Motorola, Samsung, LG and Sony Ericsson and many other mobile phone brands, and can provide power up to 24V.

And the device also has a whole array of safety options including voltage and current limitation protection, short circuits protection, anti-discharge protection, over-charging protection and over-heating protection.

The powergorilla is £150.

The company has also announced the solargorilla, which is claimed to be the "ultimate renewable powerstation for your notebook, mobile phone, iPod and many more devices".

It uses photovoltaic solar panels and all the user has to do is open the two panels and expose to direct sunlight to get the solargorilla to work.

The solargorilla has a tough rubberised casing and everything but its power connectors are water resistant.