If you don't want to make any kind of long term commitment you could do worse than pick up a V3 from easyMobile for £89.94 which includes the first £20 of airtime (£69.94 for the handset!). These can easily be unlocked to other networks if you decide easyMobile is not the one for you....

As Ben says, these are not the latest and greatest handsets, but the V3 certainly drew a crowd when it came out. There are other handsets on offer from that operator too .... worth a looksee.

easyMobile is part of the Stelios empire (easyJet etc....) and uses the T-Mobile network as an Virtual Network Operator. Tariff is flat and easy to understand. Not the cheapest around, but good value all the same. And they occasionally give away free days - unlimited no charge voice calls and text for a 24 hour period.

I've no connection with them other than being a satisfied occasional user of theirs. The other MVNOs may have similar deals on the table.