Chances of phone on contract?

Anyone had any luck getting a phone on contract? I've been here half a year so far and am looking around but don't know how easy it will be. I know buying outright is easiest way to go (not sure if its the only way) but has anyone has luck getting a contract & if so, who with? Thanks.

I think if you walk into Car Phone warehouse, you will have an answer in 10 minutes. 

Personally, I think buying a phone on an 18 month contract is nuts when you can buy a IPhone 5c new on EBay for £120.  Get a sim only deal for £10 per month and call it done.

Seconding the Carphone Warehouse suggestion.  They're really upfront and informative.

Personally I have found it cheaper, for my phone and data usage, to do pay as you go.  I bought a phone without a SIM from Carphone Warehouse for £109 and it costs £5-£8 per month for pay as you go for me. 

Thanks guys. I know about all of the other options and was just wanting to hear the experiences of others who have had luck doing this.