I can't pretend to know the inner workings of young girls, except for knowing there is a desire to wear shiny bangles and a surprising amount of blood. Ruth kikin-Gil probably has a better idea of what sort of glowing, wirelessly communicative tchotckes the young women would go for and has built her master's thesis around that arcane wisdom, designing, in concept, a group of paired 'beads' that can be used by groups of female cronies to show friendship and indicate mood.
As the group changes, so does the bracelet s composition. When two girls are no longer friends, they can remove their friend s bead from the bracelet and keep it as a memory of their friendship. When they become friends again, few weeks later, the removed beads can be added to the bracelet once again.
I'd wear this, except I'd just need one bead for myself and one for 'all of you people,' which I would then powder with a hammer.