Virginmobile.com has this LG B2100 PAYG mobile for £49.99 inc Free delivery.
This mobile comes with £35 Free air-time. Go through QUIDCO for a further £8 cashback and the total cost of the mobile after all savings is just £7 inc delivery.
Features: Triband, 65K colour screen, 640 X 480 camera, WAP, GPS, Polyphonic tones
How: Follow the above link to Virginmobile.com to buy or through Quidco for extra cashback