Apparently you can make a regular SIM card fit on an iPad.
“There is no difference between the functionality or design of a micro SIM card, when compared to a regular SIM card — the only difference is the size of the extra plastic surrounding the chip,” confirmed Carrara. “Cutting the plastic around [a SIM card] and putting it in a new device is not endangering anything. What it’s probably going to do is that people will probably not cut the plastic properly, and the contacts won’t match on the device, and therefore it won’t perform, but that’s not a problem. You can lose your SIM today and go to the operator and get a new one.”
Interesting.