After a lull of, well, some years, mobile banking is again a hot topic in America. Last week, several banks announced they would offer mobile banking applications to Cingular customers, including Wachovia, SunTrust, Regions Financial amd BancorpSouth. All banks involved will allow customers to view balances, transfer funds and pay bills via mobiles.

Today it has emerged that Citibank also plans to jump into the mobile banking game by rolling out Citi Mobile in Southern California in coming months, with a nationwide rollout to follow.

While mobile customers in Europe and Asia have been enjoying the grown-up privilege of mobile banking for a few years, the US market is just now showing a level of maturity of usage broadly that warrants serious investment in mobile financial applications. With many consumers time-poor and increasingly reliant on electronic banking, and also able to run more complex applications on their faster, more powerful mobiles, the stars are perhaps aligning for mobile banking.

Banks will have to pay serious attention, however, to issues of security, which often have American consumers skittish about any kind of remote financial applications. The banks working with Cingular will enable remote wiping of data should a mobile go missing, much like business users can do with some smartphone accounts.