Just having it doesn't make it compulsory. However, if you're sightseeing in Shawbury's Zone, it's fine to tell them just that. You can call it General Handling if you like - after all, that's what instructors from Sleap and Welshpool will be telling them. They usually give you a squawk and leave you alone unless there's any traffic close to you.
We can't squawk, either, at present. We weren't actually in Shawbury Zone - just over Shropshire, in an area where folk generally call Shawbury for FIS. For a 'wandering around sight-seing and aeros' bimble like what we were doing, there's not much value in that. And if you do initiate a call, you are then duty bound to listen to all transmissions in case there's one for you.
It's oh so much nicer not to have it on at all under those circumstances.
But, non-radio I would not like very much. Try getting into Shoreham for example on anything resembling a busy day. Your flying options are severely limited.
Thats the beauty of the on/off switch. Bimble with it 'off', switch it 'on' when that's appropriate.
As someone else said, 'use it or lose it'. I think it's an amazing freedom to be able to bimble about a large part of the UK without anyone 'in authority' knowing you are doing it. If you drive your car any distance, you'll appear on all sorts of survellance cameras. Ditto if you walk through most towns or villages, or go into a shop. The air can still be a real place of freedom, even in the UK of 2003. Treasure it! And use it! If some government busybody finds out a bunch of us are having unsupervised fun, they'll put a stop to it sooner than you can say 'identity card please sir!'.
SSD