There are many options for banks, as you point out, and mobile might be the most obvious one to jump on right now. However, the lack of consensus between banks, mobile network providers, mobile phone makers, retailers and so on creates a huge problem.
Many consumers would love to pay for things by waving their smartphone over a device, or transmitting a payment from their e-wallet of choice. The problem is, however, that without any clear direction from all of the parties in the payments chain, customers don't know what to do. Even if they have an e-wallet, they still need to carry cards for most of the retailers who don't offer any of the new types of payments in their brick and mortar locations.
Do you see any movement (in any direction) that would give customers some guidance? When will banks/retailers/mobile players start to align?