Google launched an API for Google Latitude, the friend-finding service that lets users display their locations on Google Maps.
The API, rolled out at Google I/O May 19, will let users use and reuse their Latitude location with any applications or services.
Google has put in the yeoman's work, adding controversial Location History and Location Alerts features that had privacy watchdogs barking last September. Google is even mulling a Latitude integration with Google Buzz.
However, the company now wants to outsource the work to third-party developers and has a laundry list of apps and services it would like to see developers build with the Latitude API.
Ana Ulin, software engineer for Google's Mobile team, said developers could build apps or services for that alert users to potential fraud of their credit card accounts when a purchase is made from a location remote from the card holder.
Programmers might also write apps that, in conjunction with users' location history, send alerts to users' mobile phones to let them know whether the route ahead of them is obstructed or heavily trafficked.
Some apps might even enable home thermostats to turn on and off automatically when users are driving to and from home. Again, such apps would be signaled to take action based on users' Latitude location from their smartphones.
In a lighter example, developers could write services that trigger users' Picasa or Flickr photos to appear on a map at all the places a Latitude users visited, based on their location history.
Ever sensitive to the privacy concerns such services can cause, Ulin noted that users have complete control over their location data, using it only "when, where, and how you choose."
To that end, when a user decides to a let an app or service created with the Latitude API access his location, the user must specifically grant permission to the developer to access the data and will see exactly what access or data they're requesting.
"This includes whether you share your current best available vs. city-level location or your location history if you've opted in to using Google Location History," Ulin said.
"If you change your mind, you'll be able to both see which developers have access to your Latitude data and revoke access from any developer at any time from your Google Account's personal settings. Just like with Latitude, you always choose who can see your location.
The Latitude API, which developers can grab here, will help programmers create some of the mashups Steve Lee, product manager for Google Maps for mobile and Google Latitude, alluded to in an interview with eWEEK earlier this year.
"I think it's something that Google would love to offer users. What's important in scenarios where users are looking for information between different sources is that you're transparent for end users."