What network does the iphone 4s work on?

I'm going to buy an iphone 4s from the apple online website that has a micro sim card and works on gsm networks, i'm buying it fully at 450 so its unlocked and its pay as you go, so i want to know what networks these go on? Do i just go into a phone store and get given a sim card? Or does the micro sim card i get with it get registered with whatever network i want?

Changing the battery in iPod/iPhone? - 1

What's the deal with how to change the battery in an iPod? You bring it to a store then what? Do they change it right there, Because I don;t really want them taking it with all of my data on it. I don;t know what these "Geniuses" are going to do with my personal info. I mean, yeah I have a passcode, but still.
Could someone fill me on on how that works.

And also, when the battery is swapped, do I have to put All the data back from iTunes, or is their any internal memory that can hold at least the iOS?

Added (1). The battery does not last forever. Apple replaces it.

Unactivated Iphone 5= internationally unlocked Iphone 5?

I'm going to the usa for 1 week, and would like to know if the Unactivated Iphone 5= internationally unlocked Iphone 5?

i saw it on best buy & other shops, Iphone 5 16Gb (650$-700$) "Unactivated", does that mean its unlocked? When i'm back to egypt, or travel anywhere, when i put my sim it will work?

Where to watch anime movies on iPhone 4?

I just got the iPhone 4 two days ago and I'm trying to find a website to watch Howls Moving Castle online for free on iPhone 4 or if there isn't any do you know a free app to watch anime movies or movies in general?

Trying to update my iphone 4?

I'm trying to update my phone but i'm scared it might delete my pictures and stuff so how do i save my pictures from my iPhone to iTunes. And i don't have iCloud so i can't do it through that.

I have an iphone 4s and a macbook pro.should i get the new iPad?

I have a 64GB iPhone 4s, i use it all the time.
i have a macbook pro for school and work.
i think an iPad would be awesome to have but i don't know if i would use it enough. I don't want it to sit around after a few months and be a waste of money. What legitimate reason should i have to purchase one?

Are iPhones, Nokia, etc safe?

I heard that people have been killed by their phones exploding and it happens more often than one would think but I read on one site that said all cases the batteries were counterfeit or the phone had been recently dropped or damaged or placed on a very hot surface. But another site said that phones are an instrument of death and cited a case where a chinese man had a phone in his chest pocket and it exploded and the shrapnel cut his carotid artery and the man bled to death. I'm scared because I have both an iPhone and a Nokia which use flammable batteries, what would happen if my phone shorted? Could it explode with fire or electrocute me?