I was doing research in Palo Alto for a historical project I'm working on. I was frustrated with the lack of historical information about the sites downtown and went into the Cardinal Hotel. They had photos and news clippings on the wall next to a door that lead to a barbershop on the ground floor. There wasn't much useful infromation there, but as I was about to leave, the barber came out and asked me what I was up to. I told him. He noticed my beard was a little long and sat me down in his chair while he gave me a shave and we discussed the history of the place. I found out quite a bit.
It struck me that we don't utilize the knowledge that exists within each of us who inhabits a space. The space is not a vacum but an area inhabited by people. Spaces can be enhanced by facilitating the exchange of knowledge between people in the space. This could be done through shared artifacts, through some sort of identification system that highlights people's expertice, and enhanced communication channels that allow you to query the people around you (I think Yahoo is working on something like this).