Nokia and Obopay just hooked up. Nokia, of course, is the handset giant at least outside of the US. And Obopay is a pioneer in mobile phone technology for doing person-to-person payments.

Nokia just bought a piece of Obopay. In announcing the transaction, Nokia’s director of strategic partnerships suggested that doing payments on mobile phones might become as natural as taking pictures. That may well be but there is still a lot of caution flags a ’flying. It will be a long, winding, and treacherous road between where we are today and a future world in which everyone will be using their phones as convenient devices for sending money to each other, using them to pay for things at the point of sale and paying their bills.

First, and probably pretty important, is that anyone who wants to create a payment system has to crack a massive chicken and egg problem: no one will use a payment method that others can’t accept and no one will accept a payment method that others don’t use. That problem isn’t impossible to solve but of the many who have tried it has been a rare few who have succeeded. In fact in the last several decades I can only really think of three major successes: Discover leveraged the successful Sears store card to create a general purpose payment card; and PayPal made itself indispensable to the buyers and sellers on eBay; BillMeLater looks like it will be the next in the online world. To be successful, mobile phone payment platforms must achieve critical mass among consumers and retailers.

Second, many of the efforts needed to turn today’s mobile phone into a payment instrument may be irrelevant when most mobile phones are internet-connected devices. Once that happens it would seem that payment solutions would move off into the cloud and not reside on mobile-phone specific technology. The exception of course involves the method the mobile phone uses to interact with point of sale devices.

That brings us to the third point which is that the penetration of contactless at the point of sale has moved so slowly that one needs to be very careful about betting on NFC. I’m not smart enough to say with any confidence that there’s some better alternative to contactless but I am old enough to know that given enough time technologies that we can’t even conceive of today could make today’s killer technologies irrelevant almost overnight.

So is Nokia’s move smart? If it plans to vault from being a handset manufacturer into being a global payments provider I’m pretty dubious. If it wants to keep its fingers in the rapidly evolving world of mobile payments and get some insights into how to be part of the inevitable world in which the mobile phone is a critical payment device then it makes a lot of sense.