There is much talk of Location Based Services and geographical annotation these days. We either see scary LBS (network tracks you all the time, sends you Latte coupon when you walk near Starbucks) or query based services -- "based on where I am, where's the nearest good place to eat?" That's something Vindigo does without nearing a GPS, and does it fairly well.
I've been wondering about proactive location based services and annotations that work for you and protect your privacy.
One I envision works like this. Imagine your cell phone or other portable location-aware device has a big yellow button. The button, if you press it, means "The service here sucks." Not the cellular service, but the service (or quality, or prices) in the store you're currently in. Pushing the button sends your opinion to a reputation database associated with the location.
Stores will fear the button. If you hold it up and threaten to push it, they will probably snap to attention. Why? Because you and many others will also download the database into your location aware device. If you walk into a store with a high rate of complaints, your phone will ring and warn you about where you're going.
It would probably try to electrocute you if you walked into Fry's electronics.
There are many valuable servcies when you know you're looking for geographical information, but many others that can warn you of things you didn't know to ask for. That you're walking into a bad part of town or driving into bad traffic. That you're near a historical site that's of interest to you, or a store that sells something you've been looking for.
As noted, all this can happen by pre-downling the data into a device that has the GPS-WAAS or other position information. Your device looks out for your interests based on your location, which it doesn't have to transmit to anybody. Even your vote with the yellow button can be transmitted up later, so you're not tracked in real time.