The guys at Aussie developer SecretLab have successfully trimmed down a Telstra SIM card to Micro SIM card size to fit in a 3G iPad. And they used nothing more than a pair of nail clippers to do it.
Despite the fact that the contacts size appears to be smaller on the Micro SIM, it turns out that the contacts match anyway, meaning trimming a full-sized SIM still works.
But just like when you cut your toenails, you probably don’t want to cut too close to the quick…