I am not quite sure what problem you are trying to solve. Do you have an iPhone or an iPad that you would like to use on AT&T?
Originally Posted by MacPhonev4
However, as far a I know only AT&T is using micro-sims and only for the iPad 3G. The iPad 3G comes with a micro-sim. I think that is the only source, although someone who got one that way might re-sell it on eBay. Using the device that you referenced, one can take the micro-sim in one's iPad and use it for data in one's iPhone.
If one could get a micro-sim anywhere else, one might be able to use it for data on any smartpnone.
My iPad came with 3G on by default. Anytime the device could not see WiFi it would prompt me to sign up for 3G. When I finally did (because my MiFi did not work in a particular location) it was very quick and easy to do with a credit (or debit?) card. AT&T will automatically charge my card each month unless and until I cancel the account.