Ordered one of these for my wife, I liked it so much I want one for myself. Price includes £10 airtime. Also available on T-Mobile, Orange and Virgin.
This is what "clearance" means on their website:
Handsets that have been sent out as new to our customers, but returned under the 14 day money-back guarantee. Once returned they are fully inspected, tested and reboxed by qualified Carphone Warehouse engineers, then resold as "clearance". Sometimes clearance handsets are brand new items that we have excess stock of.