Talking of criminals,although strictly speaking it isnt illegal my friend wants me to make him a wearable computer to help him when he is card counting playing blackjack(pontoon) and calculate the correct bets depending on the number of cards left in the shoe,the depth of shuffle the running count and the true count for the shoe and so on,normally all this is calculated mentally by watching the cards and trying not to give yourself away to the dealler or the pit boss.The calculations are simple enough its the interface which is difficult,do you enter hi-low counts with switches mounted under your toes? how do you get feedback?piezo electric oscillators seem the best bet,pardon the pun.So theres a good project to work on,we wouldnt pay you anything for it of course.
and before anyone asks we use a level three card counting scheme as its not really practical to do the arithmetic mentally it is ideal in a computerised system.