I just look for things to play with.
The Google Maps Android application has Google Latitude integrated in it. On the iPhone there's a separate Latitude app. Latitude is a lot like Find My iPhone but Latitude can keep location history.
On Android you control Latitude from Google Maps.
This takes you to the Latitude screen.
Chose "Location settings" to set it up.
Enable "Report from this device." If you enable "Enable location sharing" you can "Manage your friends" just below. Here you can specify who can see your current location. Your friends can not see your history.
You'll have to keep an eye on this screen. I've noticed that some times an upgrade of the Google Maps application will reset these options.
What do you get for this? Go to http://google.com/latitude to see.
This is 30 days of history. You can click through the timeline and see place by place.
Latitude is fun to play with but you need to carefully consider how much information you want to retain and share. By default Google will notify you of your Latitude settings once a month.