I dont know if this is illegal in NZ but I doubt it since its a red light and at the back.
basically. press button on remote and show ther person behind you a sad face / happy face whatever.
I know alot of you prefer the old one finger salute for things but its a bit of fun anyway.
You'd need to modify it a bit for a back/backpack
if you actually want one of these let me know, shipping from here is quite expensive so I ussually get a few people in it together to split it
http://www.thinkgeek.com/gadgets/electronic/8e9a/
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