I need a map I can display that lets the user click on a point then returns the Lat and Lng.
EDIT TO CLARIFY @Igor: Yes, the user is clicking a specific feature on the map so I guess it would constitute "tracing over imagery".
EDIT: The returned lat/lng can be fairly inaccurate, say even 10m or 20m away.
The issue is that I need the Lat/Lng data to be freely usable with no legal restriction.
For instance, from http://wiki.openstreetmap.org/wiki/Legal_FAQ
If I have data derived from OSM data, do I have to distribute it?
The licence does not force you to distribute or make any data available. But if you do choose to distribute it, or anything derived from it, it must be under the same licence terms as the OSM data.
The area to be mapped is Edinburgh, UK. Ordnance Survey is definitely not an option.
Is this going to be possible?
(We are actually going to be doing an open data service, so we may be able to use Open Street Map data, but I would like to see if there is a freely open option first.)