I read that Android (and similar operation systems, e.g. iOS) get the current coarse location by using either WiFi or GSM tower triangulation. I get the basic idea but have questions about the details. Does Android normally use both methods, or does it prefer one and fall back to the other? Does it communicate with a server to get the position via WiFi? (e.g. sending the SIDs of the WiFis to a web service) Does it communicate with the carrier …

If I'm using an Android, is it possible to know the physical location of the person who call me/ I call to?

Is there any app for Android that would assist me on tagging the pictures I take with my non-GPS DSLR camera by using a log of the phone GPS that Android can store?

When I use Google Maps it sets my Google Latitude location, but once I turn Maps off it stops. I'd like it to update with my location on a regular basis. I don't want to drain the battery by always using the GPS, but it'd be nice if it updated, say, every half hour or so.

I really wish that I could make my Android beep for business emails when at work, and home emails when I'm not in the office. Is there any applications that easily facilitates that?