Google has announced an interesting feature called Account Activity recently. It sums up what you have been doing with Google products each month, including whom you have mailed most or which places you have visited etc.
Considering the rise in the number of Google provided services in the recent years, it gives you an alarming insight in the amount of information available to Google about you. This monthly Account Activity report would even tell you the amount of time you have been spending at home, office or outside, depending on your Google Latitude check-ins.
While, this is an interesting way to look back at what you have been doing last month, it will also help in keeping a track of your Google account and you can catch any misuse. If your Google account activity report tells that you have signed-in your account from Nigeria or Guatemala despite the fact you were in India the whole time; you better change your password ASAP and take extra security precautions.
The Google Account Activity dashboard is available
here and you need to opt-in to use the service.