no
No.
No
Yes, but only if you unlock you iphone
any AT&T phone that can take that sort of sim card.
Yes, Yes you can.
You put a sim card in it.
Put all your notes into an SD card
As long as it is AT&T, yes.
Look at the top edge of the iphone 3g. there is a long button, and a headphone hole. See the tiny hole between the two? stick a small object, such as the little pick that comes with it, in the hole, and the sim card holder will pop out.
If your 3GS is locked, you can't insert a SIM card.
You have to put a small tacking chip in the sim card and download an app on your 4s to track it