Micro-SIMs were initially developed by the European Telecommunications Standards Institute (ETSI) to fit into devices too small for a regular SIM. To date, micro-SIMs are mainly found in the Apple iPad and the latest generations of the iPhone (4 & 4S).

But the small size of the micro-SIM opens up new possibilities for very small wireless devices: there could be cell phone wrist watches and cameras that connect to a wireless network that use micro-SIMs. Already today there’s a “connected” watch (Lok8u’s NUM-8) that relays the location of children from their wrists to their parents’ cell phones.