Day one of Where 2.0 was filled with social data aggregation, bottom up open geo-standards and platform owners. A couple of very nice Google demos of new deep integration between SketchUp, Google Earth and Google Maps:
KML annotation now works in Google Maps
Imagery from Google Earth can be put into SketchUp as textures
SketchUp models can be seamlessly added back into Google Earth

Everybody likes criticizing Google's perceived lack of focus and integration - but it was really hard to see any lack of integration today.

There was a Microsoft demo also of Microsofts answer for geodata. And yes, in both cases the question about the interface between the platform owner and the data creators is a big deal.
Underneath the giants we find the platform extenders: Platial and Wayfaring and all that. Some of these do personal "non serious" social stuff. Ownership is still important here, but the importance is more personal and political.
And then you have the "infrastructure extenders" like Zopto. Aggregating data on their own - but relying on the platforms for usefulness...

At the other end of the spectrum we also heard from OpenStreetMap. I'm as impressed with the project now as I was at Reboot.
Great fun and good hacking also in Socialight (very briefly), Gsmloc and most definitely the Gumspots project.

More Imity related notes on the Imity blog.