These cards operate in a manner similar to Transport for London's Oystercard travel card, in that you wave the card near to the reader and it recognises you.
It seems that Chase Bank in the US has been quietly issuing Blink RFID cards to its credit cardholders since the summer.
The RFID (radio frequency ID) cards are currently running in parallel with the normal Visa cards, meaning you have to carry two cards around with you, but Chase says the cards will be integrated very shortly.
The Blink cards have down well with consumers, as you simply wave the card over the reader, bash in your PIN or sign the slip, and you're away.
The system isn't perfect, however, as merchants are reported to have increased the range of the reader terminals to as high as 30 feet, meaning that, unless you Blink card uses PIN verification rather than signature, there is a theoretical risk you could end up paying for someone else's transaction.
It's also worrying to note that, if someone got their hand on an RFID reader terminal and set it up in a crowded location such as an airport or railway station, then they could capture the credit card data from anyone within range.
So far there are no reports of RFID-driven frauds in the US, but I remain concerned about this issue.
I'm quite happy to wave my 20 quid PAYG Oystercard to buy an Evening Standard, but I wouldn't be pleased to see my credit card limit being eaten up by any mistakes...