The video above is badly titled with the words "Tehran youth helping riot police." Au Contraire! Those few Iranian youths (three, at first) that put their bodies and lives on the line, evidently encouraging their fellow protesters not to fall into the trap of street-fighting with the cops, were not helping the riot police. They were disrupting the script upon which state repression relies.
As the state arrests and disappears leaders, bloggers, journalists, and as it metaphorically castrates the "official" opposition leadership (Mousavi), and as it engages in power struggle up above (with Rafsanjani, et al), a vacuum is created for new leadership to arise from below. Those three kids - if they are emblematic of the evolution of the struggle throughout the land (and I suspect, based on my long study of social movements, that they do) - are showing a new and improved way to fight. That their fellow protesters went along with their ad hoc leadership is a very encouraging sign.