"As an example we created the Twitter peak ">" gesture cause is fast and symbolic."

That is a problem though. It is neither fast or symbolic if you do not know it already or you have forgotten it.

What if this app had been out a long time ago and f was the gesture for Friendster?

What about a single gesture that brings up a list of actions, a further click then allows the user to post to facebook, tweet, email, or, Google it, etc.