An app that has been blocked by Apple/O2/BT has finally been given the green light,

and now it should be possible to convert 08* numbers to the underlying ordinary numbers to allow you to call the services as part of your prepay (or more cheaply on pay-as-you-go).

I havent downladed the app myself yet, but will do so at the earliest opportunity, as these buggers have been making money out of this scam for too long!