Okay folks, if you're into some kind of odd electronic mod, you may want to check out the below from a Sony Ericsson cellphone fan. The voltage released by the LED-based flash mechanisms found in many cellphone camera systems can be made into a light taser mechanism for those times, you know, when only a cellphone shock will do.
I'd say perform this modification at your own risk (this post is for educational purposes only, like every DIY Life post is
) and perhaps use as a backup to that keychain pepper spray if you're that worried about needing to fend someone off from an attack in that apartment hallway or street corner. Be advised that the Sony Ericsson cellphone model below features a 'xenon' flash system, which is the kind you'll need to scrounge up more than a few hundred volts to give that nasty-person some taser action should the need arise.
This mod will take a few small electronic additions (like adding some small-farad capacitors to store that energy), but once you locate your xenon flash-equipped cellphone of choice, have at it. Just don't use it unless you really, really need to.