Hi

I'm a south african living in seattle, moved here about 5 months ago, and picked up my iPad 3G today

I still maintain my south african cellphone account, and decided to try the simcard out in the iPad 3G

I cut the mini sim to match the size of the micro sim, and so that the contact points that appear worn match the only contact points on the att micro sim, and put the custom cut vodacom micro sim inside the micro sim tray and locked it in the ipad

I had to manually configure the data apn for the cellular network, and go turn data roaming on, but after that, all was fine, data worked and I could use my iPad as normal

this confirms two things:
a mini sim can be cut into a micro sim
the iPad is indeed not network locked