Buy a Fonera Router for a £25 once only fee and plug it into, say, your TalkTalk Router and you've got exactly the same Openzone access plus similar access in Europe and elsewhere.You can also set the Router so you only share as little as 512kb of your bandwidth
You could always just get an Amex card and get free Boingo wireless on that instead.... then you don't need to open up your router to freeloaders.