Talkmobile is currently offering the HTC Salsa, one of HTC's "Facebook phones", for £7.50PM on a 24-month contract. That’s £180 over the two years.
For your £7.50, you get 250 minutes, 5,000 texts, and 500MB of data.
Talkmobile uses the Vodafone network.
(Thanks to Adidas Addict at HUKD)