Apple has unique ways of puzzling us and here is the latest one. Apparently the iPad supports a MicroSIM standard which is almost 1/2 the size of a regular SIM card (called the MiniSIM). Apple fans around the world were disappointed that they might not be able to use the Apple iPad in their countries as very few carriers globally offer a MicroSIM currently.
However now hacks have emerged that lets you use the regular GSM / Mini SIM card as a microSIM. There are plenty tutorials on how to cut down your regular SIM card to the iPad suited MicroSIM size. However lets wait for the official 3G iPad release before we are certain about the space Apple provides for the SIM to fit in. But now you might be worrying how to use the trimmed SIM card with a regular phone?
Well here is the trick. You can get a adapter to convert your microSIM to the regular miniSIM size. Using the same you can fit a MicroSIM to any regular SIM slot as you did before you trimmed down to the MicroSIM size. What this also means is that you can take the AT&T unlimited data plan microSIM and use it on your phone (with no calling ofcourse).