Apple has proposed an even tinier SIM format to the European standards body ETSI.

The standard will take a year or two to be agreed, so don't expect super-titchy SIMs immediately or even in the next iPhone. But if adopted it will mean the SIM taking up less space in the phone.

Smaller SIMs would leave more space for other goodies, and size could become irrelevant if Apple were to succeed in its plan for an operator-independent SIM.

Apple's iPad and iPhone 4 both already use micro SIMs, which lose a lot of the plastic from the traditional SIM, but now Reuters tells us the company has proposed an even smaller standard to the European Telecommunications Standards Institute; an essential step if the smaller SIM is going to be acceptable to the GSM standard.

Mobile phones sold in Europe have to conform to the GSM standard, and that standard demands a removable SIM card to allow customers to take phones with them when they change networks. The SIM has been very valuable in driving the popularity of mobile telephony, as well as being the component that ensure the security of the whole network.

SIMs are controlled entirely by the network operator, who holds the cryptographic keys necessary to make changes to the SIM as well as authenticate customers. That's always annoyed Apple, who consider the user to be its customer and would be much happier with some form of iTunes-managed network selection rather than a hardware token beyond its control.

But until that can be pushed through the standards bodies it'll make the SIM as small as possible. The new version is electronically no different from its processors - conforming to ISO7816 and GSM 11.11 with the usual contact pattern and connections (to the relief of those who have the ISO pattern tattooed). The only difference appears to be less plastic, more fiddly to hold but taking up less space inside the case. ®