I hope I am not breaching any terms of use in posting this. I am not
being paid for it, anyway!
Finding ISPs in the UK who don't (in the small print, at least) say
you must not share your Internet connection with others seems still to
be a problem. While looking around we have been pointed to one that
has confirmed it is happy for us to share - see
http://www.upstreaminter.net/
Perhaps others would like to respond with information on other ISPs
who take a similar approach - including those who provide such a
service themselves (Helen?)