Freeview is the answer, also gets you football on Five and alternative champions league games on ITV4. Sky Sports news as well. Not bad value for around £40.
BBC3 and BBC4 are two of the VERY few new TV channels which have actually been worth watching. Seeing as you are not giving money to Rupert Murdoch, and giving it straight back to the state, go get yourself a FREEVIEW box.
According to the Freeview website postcode thingy, I can't get Freeview. I spoke to my local TV shop and he sold me a box on the understanding I could return it if I couldn't get it to work. Needless to say it got all the channels perfectly! It might be worth a chat with your local TV shop to see if they'll do the same.