Will I be charged a data plan if I buy a factory unlocked iphone?

I want to buy a factory unlocked iphone 4s off ebay. I currently have a 3g that's unlocked but I don't believe it's factory unlocked. If I put my sim card into this new 4s will AT&T know and add the data plan? I've heard this can happen before but is it just for people who buy factory unlocked phones through Apple or AT&T or is it for all factory unlocked phones?

Which iPhone is better? 5 or 4s?

I'm buying a phone tomorrow. The 5 is 200 and the 4s is 100.Is the 5 worth the extra 100 dollars? Thanks

Added (1). Yes I have sprint so thank you for that point. Also thank you captain obvious for pointing out that one is newer than the other. Real deep there

Can an AT&T iPhone 4S be switched to a different company?

Monday I found an AT&T iPhone 4S. I tried to get ahold of somebody that may of owned the phone, but had no luck. The phone was left on with minutes up till today. I was wondering if I could switch the phone over to a different company and use it as my own, or if it is just useful as an iPod now. I just wasn't sure because it is a contract phone and because it is technically not mine.

My iPhone 4 turns off and won't turn back on?

When I plug it in, it indicates the battery is charging and I'll let it get to 100%. I unplug it and works fine for a few minutes. As long as I don't put it to sleep, it'll stay on. I click the power button quickly to put it in sleep mode and that's where the problem starts. It won't turn on at all. I try to hold the home button and the power button together. I even restored it to factory settings and the same thing keeps happening. After it shuts off on me, I plug it back to a charger and it turns back on at the same battery percentage it left off.

It has no water damage:/ so I don't know what's going on. Right now, it turned off on me again (whenever it locks itself, it also shuts down). Plugged it back in and its working.

This problem is annoying me. Is it the battery? Help?

Added (1). Gave it a reset and oddly it's working. Huh, guess I underestimated the power of a reset (though I had to do it while it was plugged in)

Straight Talk On Iphone 3gs?

Can I Buy This

http://www.shopstraighttalk.com/bpdirect/straighttalk/PlanList.do?action=view&phoneFilterOptionExtensionId=13836643&productVariantExtensionId=17639196

and use it with my Unlocked Iphone 3GS?

Why does the call end after 4 hours?

Me and my boyfriend sleep on the phone at night. We both have iPhone 5's. He has Verizon and I have Sprint. Well we both have unlimited calling so we stay on the phone as much as possible. Well my phone calls cut off after 4 hours every time. Why? Like; we will be on there for 4 hours and then it will automatically hang up. But what's strange is that on both of our phones before we stayed on for 8 hours and 9 minutes. Is there a way I can fix this so I don't have to wake up every 4 hours to call him back and interrupt his sleep?

Mifi/Personal mobile hotspot thingy?

I'm going to Europe this summer like I do every year, I'm 16 and my uncle absolutely hates the thought of anyone using the Internet like completely. If you ask him to use the computer he will flip out. If you ask him for the Wi-Fi password he will flip out. So I was wondering, I wanted to get the mifi thing -AT&T unite- in white. On the AT&T website it says.99 cents (with a two year contract) I just want to know how much the two year contract part of it will cost. Because I'm going to use the mifi for my iPhone 4S and ill be gone for two months so how much would it cost for two months? And also if my phone is tmobile would I have to switch my plan to AT&T to use the AT&T unite mobile hotspot? I just would like to know the pricing of everything please. I want to have a nice summer with Internet and beaches and everything. My uncle is just too stubborn. Oh! And if it helps with the pricing too, the country I'm going to is Montenegro.

How to get music on my iPhone from iTunes?

I've been dealing with this for a while, and I'm not new at this- but I just got a new computer, and I synced my iPhone for the first time and I downloaded all my music. But when I click and drag a song from my computer to the section for the songs, the box doesn't highlight in blue, it stays gray and I can't put them on my phone. I've looked up why this is happening, and I went into the settings and clicked the box to manually put them in, but then it asks me if I want to clear my whole library. And that is a big no-no. Someone please please help!