Apple could already be testing next generation iPhones equipped with RFID (radio frequency identification) capabilities if a less than rock solid rumor is to be trusted (as if rumors could be solid in the first place).

9to5Mac admits their source, Einar Rosenberg from Nearfield Communications, isn’t exactly the end all, be all source for inside Apple info, but they have a pretty interesting rumor. Read:

A highly reliable source has informed me that Apple has built some prototypes of the next gen iPhone with an RFID reader built in and they have seen it in action. So its not full NFC but its a start for real service discovery and I’m told that the reaction was very positive that we can expect this in the next gen iPhone.

Cool. Let’s assume this to be true, just for the sake of discussion. What exactly would you do with RFID in your iPhone? A host of things actually, but the most useful for regular users would likely be how it could simplify device discovery and syncing. You could just bring your iPhone within close proximity of your next gen Mac (presumably also equipped with RFID) and syncing could happen wirelessly. Now that’s something I think we’ve all wanted for some time.

Adding to the believability of this rumor is the fact that Apple has a patent for a “Touch Screen RFID Tag Reader.” But hey, that could be for any of the other touch screen devices Apple makes…

Another use could potentially be a form of credit “card” or ever a credit card reader. This also explains the rumor source, since Einar Rosenberg is the CTO at Narian Technologies.  They are all about mobile advertising and payments, two things that could leverage RFID in devices like the iPhone.  I’m sure Apple wouldn’t mind using RFID to accept credit cards with a future version of their already new iPod touch mobile scanners they’ve recently started using in Apple Stores.  And using the iPhone like a credit card wouldn’t be a bad idea either.  I’m never without my iPhone.  Never.  I can think of several times I’ve forgotten my wallet at home but somehow managed to have my iPhone with me.  Now that I think about it, I really wish I could have paid via iPhone the last time I did that, too.

RFID presents a lot of opportunities for devices and accessories to work seamlessly with each other, and I wouldn’t be surprised in the least to see this rumor pan out.