As of 2015 there were more than 400 bitcoin ATMs globally, mostly in North America. A friend of mine is vacationing in Bratislava, Slovakia, and sent me this picture. Bitcoin ATMs work in conjunction with mobile phones. To buy bitcoin, you enter your mobile phone number on the ATM and then confirm a verification code. Next, you hold your phone up to the ATM camera so it can scan the QR code from your digital wallet. You then insert money in the ATM and the corresponding amount of bitcoin is sent to your digital wallet on the phone. You can also do the reverse and trade bitcoin for cash from the ATM. Read more about bitcoin in my blog.