As well as launch the Nokia Lumia 800 at Nokia World in London, the Finnish manufacturer has also unveiled the Nokia Lumia 710 Windows Phone, a smaller, cheaper WP7 Mango handset that also harks back to the 90s with exchangeable back covers.

Coming in black or white, the Lumia 710 (formerly known as Sabre) can be customised with black, white, cyan, fuchsia and yellow back covers. And what's the betting that a large third-party cover industry strikes up again, just like with the 3310 back in the company's heyday?

The new phone is designed for those most interested in social networking and picture sharing, and actually comes with the same 1.4 GHz processor, hardware acceleration and graphics processor as the Nokia Lumia 800, but its price is expected to be around €270 (£235) SIM-free rather than the €420 (£365) of the higher end model.

Unlike its sibling, however, which will be available from November, the Lumia 710 is not expected to hit until 2012.

UPDATE: The spec list for the Nokia Lumia 710 is now in and there's plenty on offer for a budget handset.

The screen is a 3.7-inch WVGA (800 x 480) TFT capacitive touch ClearBlack display. There's 512MB of RAM and 8GB of storage space. The processor is, as previously mentioned, 1.4 Ghz Single Core type - MSM8255 (WCDMA). And, like the 800, it seems that there's only a rear-facing camera; this time 5-megapixel, with an LED flash.

Measurements are 119mm x 62.4mm x 12.5mm, while it weighs 125.5g.

Talk time battery life is up to 6.9 hours on GSM, while standby is up to 400 hours, with music playback promising up to 38 hours.

The Nokia Lumia 710 comes with the company's WH-208 headphones, but is compatible with the new Nokia Purity Stereo headset by Monster and Nokia Purity HD Stereo headset by Monster. And, naturally, the operating system is Windows Phone 7.5 Mango.

Nokia Lumia 800 pictures and hands-on