Need to know in real time which service truck is closest to a customer's location? Want to know whether your daughter really is at the library or how your friend is progressing on a trip through the Barossa Valley?

Google just made it a bit easier to get that information.

The company Wednesday unveiled an upgrade to Google Maps that allows people to track the exact location of friends or family through their mobile devices. Google Latitude not only shows the location of friends, but can be used to contact them via SMS, Google Talk or Gmail , said Vic Gundotra, vice president of engineering with Google's mobile team, in a blog post. A beta version of Google Latitude was released more than a year ago.

"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," wrote Gundotra. "It's a fun way to feel close to the people you care about."

Scott Ellison, vice president of mobile and wireless at IDC, said such GPS technology has been available from other vendors for some time, Google's entry into the business prompts a lot of buzz.

Dan Olds, principal analyst with the Gabriel Consulting Group, said the Google tool is interesting even if there are obvious potential privacy issues when people know your every move.

"Latitude puts a powerful tool in users' hands. Parents can easily track their children. People can follow their friends' travels," said Olds. "Businesses can watch employee movements across the world or inside a particular facility. It will allow them to quickly dispatch, for example, the closest service person to a customer location. With Latitude, it can be done without taking the time to call service people to find out if the workers actually are where they think they are. The company will automatically know."

But Olds also noted that people need to think through who can access such personal information. "Users need to understand how to do it and why they probably don't want to constantly broadcast their location to the world at large," he added.

Google explained in an online statement that users can opt into the GPS feature, or allow only specific friends or family members to follow their travels. Once an agreement is reached, users will be able to see their friends' profile pictures appear on a map through their mobile device or desktop computer.

The company was quick to point out that the tool isn't for everyone all the time.

"Fun aside, we recognize the sensitivity of location data, so we've built fine-grained privacy controls right into the application," said Gundotra. "Since you may not want to share the same information with everyone, Latitude lets you change the settings on a friend-by-friend basis. So for each person, you can choose to share your best available location or your city-level location, or you can hide."

He also pointed out that the application will let users lie about their location at any time. "For instance, let's say you are in Rome," Gundotra added. "Instead of having your approximate location detected and shared automatically, you can manually set your location for elsewhere -- perhaps a visit to Niagara Falls."

That feature alone could make Google Latitude the tool of choice for workers pretending they're actually out headed to a job site, as well as for wayward spouses, Olds noted.

"I was really looking for a way to become more connected and to allow people to know exactly where I am at every minute of the day. Thank God Google is making my paranoid dreams come true," said Olds, sarcastically. "Hey, some people will see this as inherently evil technology. It's like Big Brother with a search engine. What about the employer who makes it a condition of employment that employees allow themselves to be tracked?"