When I added some credit to my phone yesterday a deal deal came up for existing PAYG customers.
-Choice of 3 phones, Sony Ericsson Naite/Samsung Beat DJ/Samsung Solid Extreme
-Free o2 - o2 calls
-75mins calls to other networks/landlines
-Mobile internet never more than £2 per day
£10.00 per month for a 24 month contract.
This is ideal for me - hope it suits someone else too.