Twitter announced in its blog last week that it is developing a new API that will let developers add latitude and longitude to any Tweet. Twitter as it stands has a “Location” field for Twitters, but it’s not linked to actual geolocation data and anybody can type anything there.

This API is being rolled-out a little differently; Twitter is going to release it to platform developers first, then to the mobile Web site and the Twitter Web site. So you’re going to see availability at different places at different times.

If you have any concerns about privacy this announcement will probably make all your alarm bells go off. But Twitter does note that people will have to opt-in to the feature, and that “exact” location data won’t be stored for an extended period of time (which begs the question: what is non-exact location data? You’ll store the state I was in at the time of the tweet? The region? The area code?) It sounds like the location feature is going to be just on/off, which is too bad. If there were a secure way to do it, it might be interesting to offer people the ability to add their location to an aggregate of information. John Doe might not want to put his location on every tweet, but he might be willing to allow his general location to be aggregated for research purposes.

Why do general aggregation of location information in addition to location for individuals? A couple of reasons. First of all, I think more people would be willing to opt in to aggregation as opposed to individual data (again, if that information can be gathered securely.) Second, it would make for some fascinating studies. Take the 2008 elections. Wouldn’t it have been great to see what parts of the country were “lighting up” with extra-high Twitter activity during the elections? Then later seeing if those areas of activity correlated with things like close elections, high voter turnout, public gatherings, etc.

I’m looking forward to seeing how this new API is implemented. Constant, real-time feedback on the businesses and institutions around you will be a cornerstone of furthering augmented reality, and Twitter is in an excellent position to provide that data.

(By the way, if you don’t have “augmented reality” as a monitored query in your favorite news search engine, you’re missing some great stuff.)