Apple spent an hour on stage in San Francisco this month showing off aluminium iPod nanos, movie rentals and a small silver box called iTV, and the only thing anybody wanted to talk about afterwards was the product that did not appear.

The phone rumour has been running for well over a year now and it refuses to die, mostly because the logic behind it is so hard to argue with. Apple has sold something in the order of sixty million iPods. It owns the digital music business outright. Every one of those customers already carries a second device in the other pocket that also has a screen, also has storage, also has a battery, and increasingly also plays music badly. Convergence is going to happen to the iPod whether Apple participates or not, and Steve Jobs is not a man who enjoys having things happen to him.

The counter-evidence is the ROKR, and it is worth being honest about how bad that was. Apple licensed iTunes to Motorola, Motorola shipped a phone with an artificial hundred-song ceiling, Cingular sold it, and the result satisfied nobody. You could not buy music on the device. You had to sideload from a computer. The cap existed for no engineering reason anyone could identify, only to protect iPod sales. It was a product designed by three companies each trying to give up as little as possible, and it showed in every interaction.

What I take from the ROKR is not that Apple cannot make a phone. It is that Apple will never do it that way again. If they build one, they build the whole thing, and that means a negotiation with a carrier that no handset maker has ever won.

This is the part of the rumour I find genuinely interesting, and the part almost nobody discusses. The hard problem is not the hardware. Apple has been designing pocketable devices with good screens and good batteries for five years and they are demonstrably excellent at it. The hard problem is that in the United States the operator decides what a phone does. The operator subsidises the handset, the operator dictates the feature list, the operator puts its logo on the front and its software on the deck, and the operator switches off anything that competes with a service it sells. Ask anyone who has bought an American phone with the Wi-Fi quietly removed.

Apple does not do co-branding and Apple does not let other people design its software. Those two facts are incompatible with how phones are currently sold in its home market. Either the rumour is wrong, or somebody at Cingular is about to agree to something no operator has ever agreed to.

The name is the other loose thread. Cisco has owned the iPhone trademark for years through its acquisition of Infogear, and there is a Linksys product wearing that badge right now. Trademark disputes get settled with money, so I would not read too much into it, but it does suggest that whatever Apple is doing, it has not finished doing it.

What would it actually need to be? Not a smartphone in the sense the industry currently uses the word. The market leaders are all competing on feature checklists, and Apple has never once won a checklist. Symbian devices do more than any Apple phone would do on day one. The N-series will out-spec it on the camera and probably on the radio. If Apple ships a phone that tries to beat a Nokia at being a Nokia, it loses.

The version that works is the version where the phone does fewer things and does them in a way that does not make you want to throw it across a room. Every phone I have used this year has a browser that is technically present and practically unusable, a music player bolted on by somebody who does not listen to music, and a text entry system that punishes you for having fingers. There is enormous room to win on experience alone, and experience is the only axis Apple has ever competed on.

I would not bet on the timing. Apple has let rumours run for two years before and shipped nothing. But the shape of the opportunity is real, and the fact that this month’s event came and went without it does not tell us much beyond the obvious: if it exists, it is not ready. What I would like to know is which carrier has said yes, and what they got in return. That answer will tell you more about the product than any leaked spec sheet.