Social networks clients: should you trust them with your passwords ?

I don't like it much when a third party web site or application requires my authentication information to, say, post a tweet in my name, or upload a picture...
Not that I doubt they can be trusted, but you never know what may happen.
Besides, in some cases, there are ways around this!

Yoono 7 does not ask for your passwords! Instead it uses authentication services provided by Twitter, Facebook, LinkedIn, where you authenticate on their websites! Yoono never knows what your passwords are.

All is explained in detail in this video:



I don't know about you, but I find that pretty comforting.