Do all the big carriers offer SIMs with plans that can be managed on the iPad itself? When I got my 1st gen iPad I had an Orange and an O2 SIM, both let me pay for plans on the iPad itself. For some reason neither of the SIMs I have will work, the O2 one doesn't even connect to the network. Where can I get one that lets me manage my plan on the device itself? I asked in the 3 store and they said none of theirs could be managed on device. Its so much more convenient than having an actual contract or having to top up somewhere.