Just as you do on Facebook, you can now tag images of you and your friends and acquaintances on Twitpic. Below the image in question, just click the blue link reading "Add/Edit Faces."
When you tag your pics, you'll also have the option to tweet out who you've tagged. You'll be able to add real names and/or Twitter usernames to the pics, and others can see the tags when they mouse over the picture.
Users will be familiar with the Facebook-like interface. Here's what the feature looks like on the site:
Last week, the service added the ability to group your photos based on the event at which they were taken. In practice, this feature works a lot like a Flickr set, letting users organize, define and showcase their pictures quickly and easily and making the discovery process easier for both humans and web crawlers.
Twitpic has also just reached its 10 million users mark and is gearing up for more group and geo-location features from this service. To get a better idea of where Twitpic might be heading in the months to come, you can check out this video interview with Twitpic founder Noah Everett on the future of Twitter-based photo sharing.
Are these new features going to make Twitpic more interesting, fun and useful for you? Let us know your thoughts in the comments.