I've been using Google Latitude since the beginning of the year on my Sony Ericsson P990i and since the end of February on my Nokia E71. It's a feature within Google Maps that shares your current location with your friends. My previous phone had no GPS so it chose my location based on the local mobile phone cell. My latest phone however has GPS built-in so it can transmit my exact location to my contacts. However, you can choose the accuracy of the location you share with people. The latest Latitude widget allows you to share your location with anyone on the web. You'll see I've set the sharing detail at town level.

With the application open on your phone, it will transmit your location at regular intervals. If you have the application closed, it will show the last location registered when you had the application open.

I've put a copy of the widget at the bottom of my blog so you'll always be able to see where I am. Try it out for yourself. Visit www.google.com/latitude.