Is Apple working on a music player cell phone? Apple’s CFO, Peter Oppenheimer, might have let the ‘cat out of the bag’ on an Apple analyst Q3 conference call.

When analyst Richard Farmer mentioned the success of the Sony Walkman Phone, Oppenheimer responded by saying: “As regards cell phones, we don’t think that the phones that are available today make the best music players. We think the iPod is. But over time, that is likely to change. And [Apple is] not sitting around doing nothing.”

So when it comes to cell phones, just remember that Apple is “not sitting around doing nothing.” Our sister blog e-Fuze thinks that “This should serve as a clear indication that Apple is indeed working on the iPhone, it is now a matter of when Apple will officially confirm the project and even release a timeframe for the device. Probably within the next one and a half years or so we should see this device roll out.”