Twitter may already be everywhere, but it’s about to know where you are. The microblogging service announced today a new feature that will make it location aware for users. 

Twitter is developing an API that will allow third-party platforms
like Tweetdeck and Tweetie to indentify users’ latitude and longitude. Eventually it will be an opt-in option on Twitter itself. And that means local advertising cannot be far off.

The new switch won’t change things much for consumers, who can already
broadcast their location and find nearby tweeters through outside
applications. But it will be a big move for developers.

According to the Twitter blog:

“A new API will allow developers to add latitude and longitude to any
tweet. Folks will need to activate this new feature by choice because
it will be off by default and the exact location data won’t be stored
for an extended period of time.”

Twitter’s Biz Stone suggests on the blog that the new feature will help users track local events, like a concert or earthquake. But he also acknowledges that “there will likely be many use cases we haven’t even thought of yet which is part of what makes this so exciting.”

One such use could easily be localized advertising. The key to making location useful for brands or even in depth event information still lies in creating an effective search engine. Twitter has a long way to go with that.

But the recent hire of Ryan Sarver, who Stone calls Twitter’s “geolocation lead,” means that the company is serious about real-time location features.

There will have to be a large mass of users allowing location awareness for local advertising to be effective, but with social media users increasingly comfortable broadcasting their personal data, that is not farfetched.

According to LinkedIn and Harris,
only 8% of advertisers currently think Twitter is an effective promotion tool. But knowing where people are could go a long way toward changing that.