This is my first deal post so go easy :)
Saw this today and thought is was a fab deal. You can sign up for the T-Mobile Combi 20 package for £20 per month on an 18 month contract. Then, you would receive £360 cashback in 5 stages through the contract (£72 paid in month 4, 8, 12, 15 and 18). This means you have 200 minutes and 200 text per month for nothing.
Fair enough the phone isn't special but you could always look at using your own handset.