Nobody wants to have their wallet or purse stolen. If you live in a place where that's likely to happen, the best thing you can do is use an alarm of some kind. Hack a Day has a guide on how to create a small pocket alarm using a magnetic window alarm.
We've talked about a few ways to deal with pickpockets before, but a good pickpocket will have your wallet long before you know it was stolen. This hack is straightforward and sticks to the car alarm philosophy of creating a loud noise meant to scare the pickpocket (and alert you) when they grab the wallet.
The actual process of creating this for yourself is easy. Using a magnetic window alarm, you just need to strip apart the case and move a couple of things around. Then, stuff it in your wallet, and you're all set. It's a little clunky, but once it's actually up and running, you can likely cut down on the form factor to get it seated in your wallet. Head over to Hack a Day for the full guide.
Quick wallet hack adds pickpocket alarm [Hack a Day]