If you're wondering why I need this, I am a secret shopper. 

Requirements

- must be able to save video up to one hour (more would be great)

- audio is a must

- low lighting situations are common

- small but powerful battery pack (rechargeable via usb?) Easy to switch out if necessary. 

- easy/discreet on off button

- option for stills 

- obviously must be disguised (though I have thought about making it look like a mini camera pendant...just for irony)

Here are my basic ideas/thoughts:

- make it from recycled laptop or phone cameras

- necklace seems to be the best option for ease of use

- use recycled computer wires/thin cables as the necklace portion and to hide the live power/video cable

- style it as a recycled circuit board and components? Industrial jewelry or something like that. Possibly have a few led that can blink as a nod to television electronics and to throw people off

- possible to monitor/check video/upload via phone app?

- possibly make or convert into brooch or tie clip for other wearable options

Issues I have identified

- not sure if it is possible to have a battery physically small enough to fit into a pendant and still have enough charge and be rechargeable. Potentially have the necklace wire (power and video) go down my back to a pocket sized battery pack.

- sd card for saving and/or pocket sized portable harddrive for wired and/or remote uploading

- would there be any type of electronics that would interfere with the signal...if there is a signal that needs to go somewhere

- audio quality problems between volume of wearer and others nearby

- audio filtering of ambient noise

- low light and low quality recording issues

- must be able to stay facing forward

- could the wearer be physically hurt by anything if there is a malfunction? Overheating protection backing. Insulation on the wires. 

- I have no idea how to do this <-probably the biggest obstacle