Nokia and O2's current trial in London of mobile phones with near-field communications (NFC) capability reminds me that there's not a lot new under the sun.
The NFC handset works in much the same way as a contactless smartcard. The trial involves it substituting for - among other things - London Transport's Oyster card as a payment method for buses and tubes, and for e-cash cards from Barclays and Visa.
It works by loading Oyster and e-cash applications onto the phone. You then touch the handset to a "secure reader" to pay for stuff.
The thing is, you don't need a mobile phone to do any of that - you can do it with a smartcard. Multi-function contactless cards with their own secure operating systems, such as JavaCard and MultOS, have been capable of running third-party applications for years.
Indeed, more than 10 years ago I interviewed a smartcard expert from Bull. He told me how the industry had started with single-issuer single-function cards, and was already moving on to single-issuer multiple-functions - cards which not only let you into the building, but also let you buy things from the office vending machines and log on to the network, for example.
He added: "Maybe in 20 years we'll get to the Star Trek scenario where the card is your property and you load any application you want."
It was a popular vision, too. The US state of Utah even proposed a multi-function smart driver's licence that would be also take third-party apps. One piece of plastic could potentially replace a wallet-full of credit cards, loyalty cards, library cards and more.
But it wasn't to happen. Despite technical safeguards to prevent one app reading another app's data, the Utah proposal was killed by political FUD-merchants who whipped up privacy fears, claiming it could give Big Brother access to your video rental and e-payment records, and who knew what else.
(Mind you, that was pre-9/11. These days it's possible a similar proposal could go through on the nod if it were sold to a fearful public as "a necessary security measure.")
Other multi-function proposals fell too. For many it was the branding issue - loyalty and credit card issuers wanted their logo on the card, not someone else's.
But now the idea is back, and like your camera, MP3 player, radio and portable games console, it's going to be in your mobile phone. The one thing most people won't leave the house without, after their door-keys that is - and who knows, in the future it could be your door-key too.
Of course, there are some big advantages to building your e-cash and travelcard apps into a phone, not least that it has a screen. That means you can see what apps are on there, how much credit you have, and how to get tech support, for instance.
It could even show the relevant brand logo as each app is activated, keeping the marketing folk happy.
The NFC handset can also be used to read smart tags - touch it to a tagged advertising poster, and it will automatically dial a number, send an SMS requesting more information, load a website, or whatever else the tag has been programmed with.
And perhaps the fact that our phones come not from Big Brother, but from companies that we already trust with all sorts of sensitive data means we are less likely - rightly or wrongly - to fear that data being compromised.
So perhaps the multi-function smartcard wasn't such a daft idea, and given that a smartcard - the SIM card - is at the heart of most mobile phones, maybe after 10 years gestation it has finally arrived.