PicoWriMo

Locally, I would say - Edinburgh council generally decorate their Nelson monument, while North Tyneside council hold a gathering at the Collingwood memorial at Tynemouth, and Morpeth's town council one at his house there. There's a service at St Paul's in London, as well (where Nelson and Collingwood are both buried), but generally I know about the northern ones - no doubt there are more little local ones in the south.

(And in the navy - I was in Gibraltar on Trafalgar Day once, and there was a fairly big formal service in the old graveyard there.)