I'm using Ezesurf at the moment; £39 up front and then a freephone number.  I don't know how long it will last, but it's already paid for itself several times over.  Connection is fairly good (though you can only stay online for 2 hours at a time) -anyway, I don't mind being cut off accasionally when it costs me nothing.  Yah boo sucks to BT, I say.

Malcolm