The Nokia 6111 phone comes free on an O2 250 Any Time Cross Network plan with 100 free SMS per month. The deal is with Mobileshop, who I've found to be reliable when it comes to cashback claims.
Free line rental is redeemed as Cash Back to your bank account in 4 stages. £90.00 at months 5, 7, 9 and 12. Full claim details are included when you receive your order. Total length of contract is 12 months.
Go through Quidco to get a further cashback of £32.50.
This is also available in PINK on the same tariff!! Read feedback in the forums... MobileShop.com are a very reliable company when it comes to cashback!!