I though this was a great deal. I have been looking to buy a Samsung Galaxy SII for some time now, and I have found a good deal for anyone who whats just the phone, and can do with a spare SIM card for friends/ family visiting, spare phone, tablet or even in your alarm (to send SMS's or make calls to you).
Phone cost: £299
Line rental: £10 for 24 months = £240
Total so far: £540 - not too bad
Orange on Quidco are offering £150 cash back for any pay monthly phone purchased (new customers only). This offer is only on for 4 more days. Be quick!
This results in a possible £390 for the whole deal.
I have just noticed Orange are out of stock of the Samsung S II now, but they could come back in to stock or get any other phone.
Spec on the Samsung SII is available here: http://www.gsmarena.com/samsung_i9100_galaxy_s_ii-3621.php