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.
Latitude is a new feature for Google Maps on your mobile device. It's also an iGoogle gadget on your computer. Once you've opted in to Latitude, you can see the approximate location of your friends and loved ones who have decided to share their location with you. So now you can do things like see if your spouse is stuck in traffic on the way home from work, notice that a buddy is in town for the weekend, or take comfort in knowing that a loved one's flight landed safely, despite bad weather.
And with Latitude, not only can you see your friends' locations on a map, but you can also be in touch directly via SMS, Google Talk, Gmail, or by updating your status message; you can even upload a new profile photo on the fly. It's a fun way to feel close to the people you care about.
I'm using this on my laptop, but I need to purchase a compatible phone at some point. It will be interesting to see how many people are willing to reveal their location in this way. If enough do, then this could be a great way to get more money from online advertising. Obviously, many businesses would be willing to pay more for ads served to potential customers who are on the same block, as opposed to in a random different city.