Mobile payment systems may be gaining only gradual steam in the US, but over on the other side of the pond, Vodafone UK has launched a broad new campaign to integrate smartphone technology where Londoners may need it most -- in the back of taxis. As of today, many cab passengers will be able to charge their smartphones in transit, thanks to a wide range of chargers that the mobile carrier has installed in more than 500 of London's iconic black vehicles. Vodafone is also rolling out a new payment scheme today, whereby cash-strapped travelers can text their cab's license
