Is it really twitter that is helping out Tunisia or is it just other people observing the event just tweeting about it. Like we saw what happened in Iran there seems to be a correlation but the causation is sort of fuzzy.

various Anon Ops also add to that. during their attacks these days quite a lot of tweets on #tunisia and #sidibouzid were from anons activity.

So the real question is how do we separate signal from noise?

Exactly. And activists' communication from foreign slacktivism, but that's another story.

The main event that started the Tunisian revolt was a shopkeeper, squeezed by a corrupt policeman and refused help by the corrupt local government, protested by setting himself on fire.

The fact we're even considering Twitter a factor here just shows how completely out of touch we are with the lives of people in dictatorships like Tunisia (which isn't amongst the worst in the region). These are places where people burn themselves in the street get attention, rather than tweet.

Last week 4 Algerians, one Egyptian and one Mauritanian have torched themselves in similar protests: http://www.nytimes.com/2011/01/18/world/africa/18egypt.html