i can put any sim in and it works? im confused now
No not until an unlock is done. If i'm not mistaken you can jail break the phone no problem with this jail break however, you will only be able to make and recieve phone calls if you have the carrier your iphone came with. So if say your with ATT and you jail break you'll still be able to use the phone however, if your with T mobile and you jail break tomorrow you won't be able to make or recieve phone calls..
At least that's what i am understanding i could be wrong about this though.