What happens if I change SIM cards on an iPhone 5?

I have an active iPhone 5 on AT&T. If I put my friends active iPhone 5 SIM card into my iPhone 5, what happens? Will I lose my contacts? Will it restore my phone? Will it change my phone to his plan? Or will it just show different contacts on the phone instead of the ones on my SIM card?

Added (1). My friends SIM card is active on AT&T. Will it just replace my phone contacts with his/

Added (2). And will it change the phone number to the new sim card?

How to add music from my iphone to the computer?

Hi, I recently cleared my laptop and put everything back on again, but I accidentally didn't back up all my music. I want to add more music onto my iphone now but when I try to sync it its asks me if its okay to remove all the music which is already on my iphone and I don't want to really loose all that music, does anyone know a way I can get all the music from my iphone back onto my computer?

My iPhone 4s (13.50GB capacity) has 0 bytes available which I know is odd?

My sister has the exact same phone and storage capacity as I do, but carries way more photos and apps, and still has so much space available (about 5.50GB). I've stripped my phone almost of every unnecessary app, photo, video, song, etc., and I still run out of space extremely fast. Can anyone tell me what's wrong or what I can do to fix it?

Did you like windows mobile? Why?

I tried iphone 4s and galaxy s3 and i didn't like none because of the operating system
they store the music in option and the pictures in wify…
i like the n8 as symbian anna and bell
i want to try something new and nice but i heard that window mobile doesn't have whatsapp or viber especially n9
is it true?
tell me everything

Media fire download problems?

So I want to download the written Thursday album by edubble for free on his website on my iPhone 4 but when it opens up to the media fire link it says oops. Then it says restarting download in 5… 4… 3… 2… 1 then it does the same thing. An I able to download it in the media fire app?

Does an iPhone 5 replacement screen fit an iPod 5th gen?

I cracked the glass but the LCD is fine. The thing is, no one has just the glass replacement for the iPod 5, but I finally found one for the iPhone 5…
http://www.tvc-mall.com/details/Front-Screen-Glass-Lens-Replacement-for-iPhone-5-OEM-Black-IPHONE5-9020A/
It says it's compatible with the iPhone 5 but I want answers.
I can't take it into an Apple Store I don't think they do just the glass and I have no way to get there…

Why did they spit on my hound?

Why did they spit on my hound?
My Vent hound (mix breed dog) was off the leash on the side of the road walking next to me
but then all of a sudden a old guy pulled over with this goth masseuse (lady who gives massages) and they spit on my Dog
i Was Freaking Out
my dog was soaking when and had corn on his ears
he looked like an iphone five charger!
what in the world do i do with him now
I have an iphone 4!

IPhone 4S Backed Up, Lost Everything?

I was trying to fix and issue with my iPhone, and was told by an Apple representative to restore my phone, then "Restore Backup". I did this to try and fix the problem, and not only is the problem unresolved but all of my contacts, messages, photos, etc have been deleted. I do not have iCloud, and the photos are not stored on my computer. I'm not too upset about the messages, but is there at least any way I can recover the approximately 1000 photos that were lost, and any of the other information if that is possible?

Added (1). I backed up my iPhone after restoring. That's what the Apple representative told me to do. I'm starting to think I wasn't supposed to do that… Regardless, is there any way I can recover what I lost?

Why did they spit on my hound? - 1

My Vent hound (mix breed dog) was off the leash on the side of the road walking next to me
but then all of a sudden a old guy pulled over with this goth masseuse (lady who gives massages) and they spit on my Dog
i Was Freaking Out
my dog was soaking when and had corn on his ears
he looked like an iphone five charger!
what in the world do i do with him now
I have an iphone 4!
the

Added (1). THIS IS WHY I'VE BEEN So like an airport by hemming way's far neck

IPhone 5 iMessage not working? - 1

I have an iPhone 5 on Verizon but iMessages aren't working. I know that iMessage was down a few days ago but everyone I know with an iPhone has it working again. I tried a hard reset and turning iMessage on and off. I've never done a restore. I would prefer not to because I don't want to risk losing my contacts. Any advice?