Don't know what ISPs you're looking at, but every one I've seen has a monthly contract option. You usually have to pay a setup fee to cover BT's extortionate 'cut', but getting out is easy-as.

I think the idea is that, much as with the NHS, it relies on economies of scale for funding. Much as you can't really opt-out of National Insurance contributions (as the rich who contribute the most are those most able to afford private healthcare - making the system unaffordable), the BBC provides so many high-quality public services, that it would be cut back so drastically by those who would just opt for things like The Murdoch network...I mean Sky ;) Other broadcasters would have to be so over regulated to provide the same level of impartial service as the BBC that you're probably better off with the current system. Really, it isn't that much to pay for the best broadcaster in the world.

I do in Firefox, but in Thunderbird I have javascript disabled and the bars are an inconvenience. On my N95 phone however, slashdot is now dead to me, as I cannot read any damn comments on the screen. It was awkward enough before, but now it's just grey bars of death time.