Visited 11th October 2003: Easy to find and relatively easy to get at. We asked about the stone at the museum, and although they couldn't help at the time I got some information from them through the post (currently 'misplaced'). Not exactly a megalithic wonder, but if you're in the Peterborough area then you're not spoilt for choice.
The stone is located on the green outside Peterborough Museum. The notice indicates that the "Neolithic standing stone was moved from a nearby location and re-erected here". When I visited, there was a temporary exhibition featuring a life size figure of LaraCroft - Tomb Raider. Strange item for a museum, but I suppose that most archaeological exhibits in museums are from raided tombs!