On a computer, having to fill out a form and type in a credit card number to buy something is only mildly annoying. On a cellphone, it could make you want to skip the purchase entirely. This is why investors, start-ups and major corporations are pouring money into services that make it easier to use cellphones to buy goods and transfer money. The aim is to turn phones into virtual credit cards or checkbooks, enabling the kind of click-and-buy commerce and online banking that people have come to expect on their PCs. But shrinking down those services to fit onto cellphones presents serious challenges. The services must work on many different phones and through many cellphone service providers, which usually control the billing relationships with customers. That adds complexity to the already tricky business of safely and securely transferring funds among financial institutions and merchants.
