Twitter has turned on a feature that lets users geotag tweets directly from the web site. So now you don’t have to rely on mobile apps like Tweetie to triangulate where you are. The move should help add location data to a greater share of conversations flowing through the microblogging network and enrich local discovery and search.

Right now, the feature is deployed to only 40 percent of users, according to spokesperson Sean Garrett. In personal tests, it works on Firefox for me, but not Chrome or Safari. You can geotag your tweet to a specific point or to a general neighborhood.

To be clear, the site doesn’t automatically geotag all of your tweets. You have to change the settings on to enable location-sharing in general. Then you have to agree to share your location in Firefox, and then you can choose where to geotag your tweet from. (See image below.)

Yesterday the company started showing geolocation on its website more prominently. You can hover over location pins on your Twitter feed, and a tiny map will pop up showing where the tweet was sent from.