Google introduced a new service called Google Latitude that allows you to share location based information with your friends in real time.
Google’s blog post explains
How often do you find yourself wondering where your friends are and what they’re up to? It’s a pretty central question to our daily social lives, and it’s precisely the question you can now answer using Google Latitude
Getting started with Google Latitude is very simple. Just install the latest version of Google Maps Mobile 3.0 (only available for Android, BlackBerry, Windows Mobile, Symbian S60 and iPhone version is coming soon) and star sharing your location automatically with the selected friends and family members.
The list of complete things that you can do using Latitude:
After selecting yourself, you can:
– Change your status message across Google products. Your status will only be shared with your current Google Talk or Gmail chat friends.
– Change your photo across Google products.
– Submit or edit your phone number in Latitude for your friends.
– Edit your privacy settings for all friends.
After selecting a friend, you can:
– Show the friend in map view.
– Search for places near your friend.
– Call if a phone number is available in your Google Contacts or Latitude.
– Chat using Google Talk or Gmail chat if available.
– Send an email.
– Get directions to the friend’s approximate location.
– Set sharing options. You can choose to hide your location or share only city level location with individual friends.
– Remove the friend. Your friend cannot see your location and you cannot see the friend’s location.
Check this introduction video from Google