Until now the only way to know what your friends are doing in real-time was through Twitter alone. However, a new service by Google called Latitude, plans to add the 'Where' to the 'What' by allowing you to see where your friends are in real-time and likewise allows you to share your location too.

Latitude is a new feature for Google Maps for mobile devices and is also available via iGoogle on desktop and laptop computers. As soon as you opt in to use Latitude, you are able to share your current location and are also able to see location of your friends on the map. Good thing is, that the whole system has been stuffed with fine-grained privacy controls which gives user the liberty to take full control of everything.

Another feature which makes Latitude amazing is the ability to get in touch with your contacts by either sending a text message or chatting via Google Talk.

A video intro of Google Latitude can be seen below.

Though I am sure Latitude is here to stay for long, but it is definitely in tough competition with the long-old service of the same kind named Plazes. Plazes has been in scene for a long time and as compared to Latitude, it has even more features to offer.

You can experience Latitude on your desktop by simply going to Google Latitude and adding the Latitude gadget to iGoogle.

To install the Latitude app on your mobile device, visit http://google.com/latitude on your mobile phone. Android, Blackberry and Windows Mobile phones are supported currently and support for iPhone is coming soon.