It isn't as though the lunar maximum occurs once and then goes away again. It's more like a coastal tide that gets higher and higher each month until it reaches a maximum (the end of September 2006) and then seeps away again for the next nine years.
Many megalithic monuments have the most southerly moonrise as a prime azimuth. It's quite likely that strange things happen with them at the lunar max. Moons fitting horizon notches and skipping along a sacred hill on the skyline type of thing. The moon is getting close enough to the southern max. now to start making observations already.
There's about a dozen sites worldwide where these observations are taking place. These include Callanish (and Smithills, on the outskirts of Manc.) but not - yet - Avebury which, some might argue, has this lunar azimuth (from the back of the Z-feature looking out of the southern entrance) as a key element of the original plan.