Twitter Supports Geotagging
Twitter geotagging is now officially available, though only through the API — which means that third-party applications can do things with it, but it won’t show up in the web interface. It’s off by default; users have to enable it. More information on Twitter’s support page. For developers, this page talks about best practices for implementing the geotagging API.
It also looks like Twitter is using Yahoo’s WOEIDs rather than lat/long tags, which makes sense for its brevity.
Update, Nov. 20, 11:50 AM: PC World: Twitter Geotagging: What You Need to Know (via Glenn).