You know how I have said that what a blind woman really needs is a personal security bubble

[kestrell]

capable of delivering a small electric shock to people who invade her personal space and grab/drag her about?
The Yellow Jacket iPhone Stun Gun seems to be it
http://www.indiegogo.com/yellowjacket
(note that it also acts as an additional power source). Okay, so it's not really a bubble, but I think it would convey the appropriate message, although I still think there should be a recorded message which warns "Step away from the blind woman."
iphone