So far, when a user was in a particular city or town, that location was automatically visible to contacts as a dot on a map. But now, with the use of Google Maps 5.1 for Android, users can actually specify their exact location, when they are in a restaurant, theatre or any other place of interest.

Of course, users retain the right to decide whether or not to share their location. Users can choose to keep their location confidential, share it with friends or even make it public.

To remind the user to use this facility, Google Maps will show a notification to check in, whenever the user enters a place of interest. The user can also opt for an automatic check in facility for certain selected places. When a person checks in at a given location frequently, that person is given a designation such as ‘regular’, ‘VIP’ or ‘Guru’, depending on the frequency of visits, which is similar to Foursquare’s system of awarding “mayorship”.

Latitude also automatically checks users out of the location once they leave the place, which is not something Foursquare does. The check in facility also provides turn-by-turn directions to the place through the Google Maps Navigation and allows users to leave reviews about the place. Google will shortly add a feature that will provide a complete history of the check-ins through an optional History tab.

Considering that latitude is used by 10 million people every month, this new feature should gain popularity very soon.

This new check-in feature is very similar to what other sites such as Gowalla, Foursquare, Loopt, Facebook Places, Scvngr and Whrrl provide. However, the additional features of notifications and automatic checkout should help Google get more users. The competitor websites will have to be on their toes if they wish to survive against Google’s onslaught.

Latitude works with Google Maps on mobile handsets as well as on a desktop. Users who add this service on iGoogle or download the latest version of Google Maps on their mobile phones can join Latitude and then invite their friends to join. If the friends accept and share their location, they can see where they are, in real time, on the map.

The system makes use of a digital map, where the coordinates of the handset being used are plotted by triangulating the location of the nearest mobile communications towers. This is merely an extension of their My Location service that was launched in December 2007.

The service has its benefits above and beyond the obvious social aspect of knowing where one’s friends are. For example, people can keep track of each other in a very large gathering, or parents can keep an eye on their childrens’ whereabouts.

There are concerns that using such a service would allow Google to invade an individual’s privacy. As David Perez of Arete Consulting put the point across succinctly, “I do not want my mother to know where I am!”.

Users have the choice to accept or refuse an invitation to join the service. A user’s location is revealed only to those members whose invitation has been accepted. Moreover, one can also choose to change the privacy settings for individual contacts in their friends list. Users can also manually input a fake location if they wish to hide their true location from a particular contact.

While Latitude is free to use, Google will most likely start serving location-based advertising to monetise the service.

At present, the service is available on Android phones like the T-Mobile G1, iPhone and iPod touch devices, most colour BlackBerries, Windows Mobile 5.0+, Nokia Smartphones and Java-enabled mobile phones in 27 countries including the USA, most of Europe and India.

To start with, this service will only be accessible on BlackBerry and some Java enabled phones, but they hope to bring this technology to other handsets in the near future.

Google Maps for Mobile will now be capable of the same level of imagery as the desktop version, i.e. it will show a 360 degree view of the point in question.

This new feature will help users to pinpoint the exact location of a shop, restaurant, office theatre etc. when they are on the go in an unfamiliar location. All they need to do is click on “Street View” on their mobile phone. They will then be able to see the appropriate street with all details in it, so there is no chance of missing the store, restaurant etc. and having to run around in circles. Even tourists should now have no difficulty going around a new town with the help of this service.

There is also a section here that gives detailed information about bus, train and ferry services to and from different locations along with the fares and timings of the local transport available.

It will be possible to use Street View from any location for which photography is available to Google. It is also possible to click on the map, and select Street View. Street View can be seen on the full screen or as an overlay on the map. The view can also be rotated to see the surrounding area from different angles as one proceeds along the road.

Another feature that Google has incorporated is ‘business reviews’, which will allow users to check whether or not a shop actually sells what the user is looking for, before making a trip down there.

It is also possible to go from one place to another on foot, following the walking directions which have been incorporated. (this feature is presently in beta.)

Google has also increased the speed of these search operations and improved the accuracy of location of a place, under their MyLocation feature. According to Brighthand.com, the MyLocation feature will work best in thickly populated places, which will obviously have more cellular towers, thus improving the cell tower triangulation on the user’s smartphone.

The latest version of Google Maps for mobile can be accessed at google.com/gmm.