Vodafone are doing a deal with the nokia 5800. 18 months at £35 with 10 months half price line rental, automatic no redemption neccessary. That works out to £25 a month. Then £90 quidco, works out too £20 a month and you get a last minute voucher for £50 with it.
And it includes 600 mins unlimited texts and mobile internet.
you could sell the £50 voucher aswell making it even cheaper.