Useful explanation from LinkedIn

Useful explanation from LinkedIn

Branch uses an anchor icon for its local anchor permalink

Branch uses an anchor icon for its local anchor permalink

Posterous lets you sign in with Facebook or Twitter to comment.

If you sign in with Twitter and check you want to post to Facebook, it pops up the Facebook oAuth window after you hit comment while simultaneously posting your comment to the blog via an ajax call. They also have a very nice tweet composition window.

If you send a chat message on Facebook and the recipient is offline, you can turn it into a regular FB message with one click

If you send a chat message on Facebook and the recipient is offline, you can turn it into a regular FB message with one click

Tweetmeme explains why it wants access to your Twitter before showing you Twitter’s oAuth page

Tweetmeme explains why it wants access to your Twitter before showing you Twitter’s oAuth page

From formspring.me’s inbox sidebar

From formspring.me’s inbox sidebar

Tumblr allows anonymous Formsping.me-type questions, but warns you first

Tumblr allows anonymous Formsping.me-type questions, but warns you first

DonorsChoose.org has this excellent tabbed interface to help you share word of your donation (and encourage others to join you) after the credit card screen

DonorsChoose.org has this excellent tabbed interface to help you share word of your donation (and encourage others to join you) after the credit card screen

Tumblr’s processing video hold message

Tumblr’s processing video hold message

Meetup.com has a nice notification of new features that feels like an inbox