I did give that some thought, there are a couple of problems with it at our location though. First, we haven't lived there long, so it might not be easy to set up an agreement with neighbours; second, it's a rural location, the houses are well spread out and we would probably have issues sharing the signal adequately; third, two-way satellite broadband systems (you couldn't share a one-way system IMO, as you still rely on dial-up for the upstream) retail at over £2,000 in the UK; and finally, I wouldn't trust anyone else to manage the system, and I can't do it as sat modems are all USB only at present, with no drivers for Mac, which is my home computer of choice.
Snookered!
Nice idea though, thanks for the suggestion