The Nokia Lumia 710 is on offer at Vodafone UK for £150, accompanied by a 6-month Zune Pass. The Windows Phone was made available on both Vodafone and Three earlier last month for £199 (though Vodafone reportedly dropped the price to £150 soon after). The Lumia 710 packs a 1.4 Ghz processor, 3.7" screen, 5MP camera, 8GB storage and sports a handful of pre-loaded Nokia apps.
Hurry up should the offer intrigue you as it ends on March 31st. Ignore the 3/5 rating as this was left by a single Android-orientated reviewer who complained about the lack of storage for music lovers (Zune Pass / Nokia Music anyone?).
Source: Vodafone UK, thanks Vicky for the heads up!