Nokia's £13 phone with a battery that lasts a month - and other new handsets

Nokia's long-lived handset was one of several unveiled today at Barcelona's Mobile World Congress - a testing ground for new ideas in mobiles.

Struggling Finnish smartphone maker Nokia has launched a budget mobile that costs less than a cheap rubber smartphone case - and has a battery that lasts one month per charge.

Aimed at developing economies and users in remote villages, the Nokia 105 will cost £13 and contain potentially life-saving features including a torch and FM radio.

It was one of several outlandish devices unveiled today at Barcelona's Mobile World Congress - a testing ground for new ideas in mobiles and smartphones.

The 'candybar' device marks the end of an era for Nokia - the 105's colour display means that the firm has now produced its last phone with a black and white screen.

Samsung's eight-inch Galaxy Note is 'the world's biggest mobile phone'.One of four phones announced by Nokia at this year's Mobile World Congress, the company hopes the ultra-budget device will broaden its appeal and help it to establish a dominant position in both China and India.

Other companies aimed for Western consumers - and phones seem destined to get even bigger, and faster than ever.

Samsung Note 8.0 is described as 'the world's largest mobile phone' - it is an 8-inch tablet with full smartphone capabilities.

The size of an iPad mini, its combination of 3G and WiFi provides users with the option to make phone calls - as well as download the latest apps, games, movies and music.

The high-end device runs the latest Android software and is powered by a 1.6GHz quad-core processor which provides the power for advanced functionality such as the pen enabled screen.

The Note 8.0 is due to hit stores in the UK this spring.

Japanese technology firm NEC has announced the world's first folding smartphone.

The innovative NEC Medias W has identical 4.3-inch touchscreen on the front and rear. The latter is mounted on a hinge and flips out - thus turning the device from a smartphone into a tablet.

While NEC's smartphones have failed to take off in the UK in recent years, the brand is still hugely popular in Japan, where this split-screen device is due be launched next month. A European prototype is currently in the pipeline.

People look at devices at the Samsung stand at the Mobile World Congress in Barcelona, February 25, 2013. The GSMA …

Described by Huawei  as 'the world's fastest 4G smartphone', the Ascend P2 supports download speeds of 150 megabytes a second - enough to download 2,250MP3 tracks a minute.

While the Chinese firm is quick to point out that those figures are dependent on the user's network connection, the device also aims to tempt early adopters with a large, 4.7-inch HD touchscreen and a 13-megapixel camera.

The Ascend P2 is due to cost £350 and will go on sale in Europe in April.

A hugely popular smartphone brand in Asia and Africa, ZTE has launched the first smartphone based on Mozilla's Firefox operating system - a cheaper alternative to Google's Android.

With a basic suite of features, a positively Jurassic 3.2-megapixel camera and a low-resolution 3.5-inch touchscreen, the compact device is set to appeal to both emerging markets and those who need a second - or even third - phone.

Its success hangs entirely on whether Mozilla can drum up enough support from third-party app developers - though essentials such as mapping and email apps are already in place.

ZTE are set to launch the device in emerging economics this year - with a European and US release date scheduled for 2014.