Orange Dolphin 25 Tarriff (£25 per Month, but 6 months 1/2 price)
300 Anytime Minutes,
Free 8gb memory card
6 months half price line rental (through cash back) - therefore, £525 in total less £50 quidco takes it to £475!
Free phone as well. This is the cheapest deal out there so far.
NB: This deal was mentioned previously on the forum but no 1/2 price line rental was on offer then.