I saw a headline the other day about how a new wave of smaller GPS chips was coming out that was going to make all sorts of personal electronic devices "location aware". This got me thinking about how the actual locations might become aware of the electronics. That sounds a lot like privacy intrusion, so maybe we step back a little and have it more that you opt-in to be in a database (like a grocery store discount card), and when you're in a location and communication links to your cell phone then the location knows you are there. This might already be happening for all I know. I remember in the movie "Minority Report" Tom Cruise is running through this mall and the Gap electronic billboards start trying to sell him personalized items, and science fiction tends to be not too far ahead of reality in things like that.
Anyhow, what I think would be really interesting in terms of this concept in public space is how an environment might alter to accomodate your personal tastes. For example, the outdoor lighting at night might shift to your favorite color.... or maybe the dominant favorite color based on the group of people connected. So, if the space is green, and then it starts to shift to red you know something about the people around you. Or maybe the color isn't based on a favorite color, but is instead a mood indicator based on your Facebook status... such as "Aaron is feeling jubilant." So the night lighting works like a public mood ring.
What if actual elements in the landscape changed, such as the shifting of various plaza levels. Maybe for the person into parkour, you get a crazy terraced landscape, but for the wheelchair bound visitor the grades shift back to ADA compliance.