Okay, if I wanted to demonstrate how much attention the Somme got, I think this might manage it. Below is a very incomplete and soon to be updated list of online sources/articles and listings. Perhaps of most interest: the continuing localised nature of commemoration, not just in Northern Ireland (where it might be expected), but in England as well. And everybody, obviously, thinks that Henry Allingham is great.
Museums, Memorials and Exhibitions
Local and Regional Exhibitions (just some examples)
Commercial and Tourist Sites