One of the biggest questions with cryptocurrencies is where to actually store your Bitcoin so that they are secure. Well, entrepreneur Martijn Wismeijer, who is also known as “Mr. Bitcoin,” thinks that he has a possible answer. Instead of trusting in online exchange and wallets, or even an encrypted wallet in a smart phone or other digital device, Wismeijer decided to invest in a US$99 NFC (near-field communication) chip from Dangerous Things and have the device surgically implanted under the skin of his hand at a bio-hacking event last week that was sponsored by Permanent Beta. The device is able …