[Pø†øƒGøLÐ]

Yes - you can pay for a service called Anonymous Caller Rejection which gives all anon callers a recorded message saying "the person you are calling does not accept anonymous callers - please redial using 1470 prefix"... or something like that.

I have this on my line - albeit it's TW and not NTL - but I believe all telephone operators offer something similar. I think it's something like £1 per month but can't remember.