Wearable tech/gadgets

Does anyone here have any wearable tech/gadgets? They seem to be picking up steam and becoming quite popular. I guess i'm curious as to how helpful they really are and if they are maybe the future? I do find wearable tech like google glass to be quite cool. However ive heard about major backlash from people wearing them in public areas(Bars etc...). Sometimes even leading to arguments and fights. Wearable tech like google glass does raise some serious privacy concerns which I think are very legitimate. What do you think?