Quick post…
…trick.ly is a URL shortening service with a brilliant hook- you can add a good layer of privacy. Here’s an example http://trick.ly/3hC:

It works because it relies on the person opening that URL knowing the key. Others could guess, but why bother? It doesn’t look like it could stand up to a dictionary or brute force attack, but that’s not what its about.
The blog uses beautifully simple language to make their case:
“We wanted to create an easy-to-use security system for tribes.”
The word “tribe” is important- it describes in some way how people behave and interact on Twitter.
Previously it would be impossible to share an event, some private news, or even a coupon to a selection of followers, but now (with the right question/password combo) that is realisable.
It is simple, and because of that it is beautiful.