Designed for use at EFTPOS and ATM terminals, the service uses a mobile phone and GSM signal triangulation to authenticate the user's location and that it really is you.
Punters download the mConfirm client software to their mobile, which then locates itself based on the Geo Spatial GSM location data service and interacts with the card issuer's network.
When the user's card is swiped at the EFTPOS terminal or at the ATM, the mConfirm servers are notified that a transaction is taking place, at which point a location request goes out to the user's mobile, without the user being asked for confirmation.
If the user has his/her mobile in their possession, the transaction can be silently authenticated.
What I find interesting is that the technology isn't designed to be bullet-proof, but acts as another layer of security for the card companies.
It also means you;d better not leave your mobile at home when out shopping, but that's another story...