Retailers who believe that m-commerce is a long way off should think again with the news that there will be two mobile phone subscriptions for every three people in the world by the end of this year.

The announcement, from the International Telecommunication Union (ITU), that there will be 4.6 billion mobile phone subscriptions by December 2009, is accompanied by another interesting statistic, about the rise of mobile broadband. The ITU estimates that mobile broadband subscriptions will top 600 million worldwide this year, overtaking the number of fixed broadband subscribers which will reach 500 million.

So people around the world are increasingly accessing the web while on the move; whether it is from mobile phones and other handheld devices, or larger netbooks and notebook computers. Consumers are increasingly no longer confined to the home or office when they are looking at your website, or one of your competitor’s.

The user experience of trying to browse the web from a phone is quickly improving with developments such as the Apple iPhone, and other larger format mobile devices running Microsoft’s or Google’s mobile operating systems. But retailers have generally dismissed m-commerce as being an essential channel to market so far on the basis that consumers, in the UK at least, aren’t yet comfortable making purchases on their phones.

Research out this week from ecommerce systems provider ATG suggests that more than a third of UK shoppers have tried to shop using their mobile phone, and they have not been overwhelmed by the experience. But a similar figure say that they would be more likely to shop online from a mobile if retailers provided secure and easy to use payment services.

In the US, Amazon is trying to break this chicken and egg deadlock. On Monday it extended its 1-Click checkout proposition to developers of mobile applications and other retailers with its Amazon Mobile Payments Service. This will allow customers to make payments to other retailers on their mobile device using the information in their existing Amazon account.

One prominent UK multichannel retailer recently commented that they thought m-commerce was still five years away. The growing body of evidence suggests that retailers who leave it this long will be playing catch-up with their customers.