What was there?

Here's an interesting project that extends the Museum of London Street Museum application to map historical photographs through crowd sourcing. I suppose ideally it would balance individual and institutional data, but open source projects can be limited by copyright restrictions and the occasional insular archive. Hopefully it will become a really useful resource.

http://whatwasthere.com/

There's also a free app for iDevices if you're that way inclined:

http://itunes.apple.com/us/app/whatwasthere/id421576457?mt=8&ls=1