Social media moves so fast, it's hard to keep up. Here are the week's top stories in scan-friendly format:

  • Facebook Enables Facial Recognition
  • WordPress.com Blogs Now Allow Comments from Twitter and Facebook Users
  • Online Sharing: Facebook Accounts for 38%
  • Twitter, Coming Built-In To Your iPhone or iPad

Facebook Enables Facial Recognition

Facebook recently turned on facial recognition globally, meaning the social network will now help you tag friends in photographs using algorithms. Now, as your friends upload photos into their albums, Facebook will try to figure out if any of the images look like you. If the system believes it finds a match, the website will prompt you to tag it with your name.

This feature may sound like an amazing piece of technology, and it certainly is; however, think about the Facebook friends of yours who may not want to be automatically identified in photos. Perhaps they are in a shot taken at a party that they don't want their entire Facebook friend list seeing. The issue here is not in your Facebook friends tagging you in photos -- rather, that Facebook is now pushing your friends to go ahead and tag you.

This privacy concern can be addressed by Facebook users by disabling the feature in Privacy settings. See this post for more information. How do you feel about being automatically tagged in photos? Does it creep you out? With employers looking at Facebook profiles constantly, does this concern you?

WordPress.com Blogs Allow Twitter, Facebook Comments

Those who like to leave comments on blogs have long complained of one minor nag when conversing with bloggers. On most blogging platforms, you must either have an account or leave your email address along with your name to leave a comment. For the 20 million blogs hosted on WordPress.com, this nagging and security problem is now solved, that is, for users of Twitter and Facebook.

When leaving a comment on a WordPress.com-hosted blog, Twitter and Facebook users can now leave comments using these credentials, making it unnecessary to create an account on each individual blog. WordPress puts it best when this new process "gives visitors control over which identity they can use." It should be pointed out, though, that this new feature is just a one-way identity play, meaning your comment left on a blog won't be published on your Twitter timeline or Facebook wall.

This move continues the "identity war" online, whereby players such as Google, Yahoo, Twitter and Facebook are looking to be your online identity and therefore the source of your online identity. According to WordPress.com, more integration is coming with Facebook and Twitter in the near future.

Online Sharing: Facebook Accounts for 38%

When you find a cool link, video or picture online and you want to share it, what facility do you use to alert your co-workers or friends about it? The options may include email, Twitter, Facebook, bookmarking sites or even instant messaging. Of all the vehicles for online sharing, Facebook is used in almost four out of every 10 cases, according to ShareThis,  the popular online sharing utility used by online publishers.

By analyzing actual usage online, sharing produces about 10% of all Internet traffic and 31% of all referral traffic to sites. By comparison, organic search is still twice as big for driving traffic. In terms of sharing drivers, Facebook accounts for 38% of all sharing online, followed by email and Twitter with 17% each. However, when looking at actual click-through rates, Facebook is an even bigger player, accounts for 56% of all shared content.

These statistics should alert publishers that enabling sharing via Facebook, Twitter and email, according to these numbers, will give the best return for your effort.

Twitter, Coming Built-In To Your iPhone or iPad

At the recent Apple developer conference, Steve Jobs and his cohort of executives gave us insight into the future of the software that powers iPhones, iPod Touches and iPads. Among the many bells and whistles previewed on Tuesday, the surprising one for social networking fanatics was the built-in support for Twitter, making the service the default social graph and social network on iOS-powered devices.

Rather than interacting through the siloed experience of a standalone application, you'll be able to interact with Twitter from the iPhone software itself. This means you can tweet from onboard applications such as Camera, Photos, Safar, Contacts, YouTube and Maps. Twitter integration also means you can have your contact list enhanced with profile photos and usernames of your Twitter friends.

The verdict is still out on why Apple embraced Twitter and not another social networking service, such as Facebook. However, the move is great news for Twitter, because now the service will be more accessible and easier to use for iOS users, and there are hundreds of millions of new users that are within reach for Twitter.