The first time in ages I have mapped anywhere that has taken me less than an hour to reach by public transport. A fairly typical Cambridgeshire village, population just under 3,000, though it was apparent from the bus up from Newmarket that there was also a lot of industrial development south of the village, which I was able to complete as well. There was a skeleton of streets in place, but only about 20% completeness previously. Fordham has a rather magnificent water tower (http://www.geograph.org.uk/photo/252313).
There's a chunk of Soham on its southern edge which is not complete, (which almost merges into Fordham), so a good combination for another day would be that plus the village of Isleham, a couple of km further east.
However, I hadn't realised that when I was there, so instead headed south and filled in a small chunk of Newmarket (off George Lambton Avenue) where housing was under construction last time I was there. It's moved on quite a lot, but there's still construction going on. But three new streets have materialized.