These are in the UK:
- Evesham Mapped - presents some of the 'hidden' data that doesn't appear in the standard OSM map renderings.
- Mappa Mercia - aiming to grow OpenStreetMap in the West Midlands of the UK, they support local organisations wishing to open up their data
- OSM Nottingham presents data that has been added by volunteers in the Nottingham area
For a wider vision see the
Historic Place Map, as described in
this blog post.