What is 3G for the iPhone 4? Can I turn it off and still use the internet?

I just got an iPhone 4 two days ago and I'm noticing the battery isn't the greatest so I'm reading reviews on how to save the battery life and someone said to turn off 3G. What is 3G, what does it do and can I still use the internet if I turn it off?

My plan is just prepaid, no data, I only use the internet when I'm in Wi-Fi range.

Saving photos to a separate album on iPhone?

I would like to save pictures from I funny and wallpaper apps exc to my phone but I don't what them in my camera roll with my real pictures. I can save a photo to an album but it also saves to camera roll and if I delete it from camera roll it goes away from the other album as well. Is there a way to save the photos to the separate album and not camera roll?

IPhone Lego Harry potter years 5-7 year 6

I'm playing Lego Harry potter and I'm on year 6 and I'm in the cave And I can't manage to opens the cave door? I suppose it's a cave door. I need to use the deluminator to open the door any help I'm playing it on the iPhone 5.

IPhone 5 won't play youtube when phone is locked?

I listen to music via youtube but my iPhone 5 does not let me play it when my phone is locked. I'm aware of how you are supposed to do it (double click home button then click play) but it just plays songs from my music library? My cousins phone does it so why doesn't mine we have the same phone aswell.

Should the Obamaphone program give out iphones to save peoples lives?

Man Recovering After Being Shot Over An iPhone (Chicago)
http://chicago.cbslocal.com/2012/12/27/man-recovering-after-being-shot-for-an-iphone/

Original Obamaphone Lady: Obama Voter Says Vote for Obama because he gives a free Phone

(She coined the phrase "Obamaphone" regardless who started the program.)

Added (1). Wake Up - is good example of a Moron that didn't read the whole question.

What does LTE mean on iPhone 5?

Just got iPhone 5 and it often comes up with LTE at the top for signal… What does it mean? And does it mean that my phone is not using Wi-Fi? Does it use the data plan?

How to use a PAC code on O2?

I currently have a PAYG sim on orange and i have just bought an iPhone 5 on contract on 02. I was wondering if anyone could tell me how to use the PAC code to transfer the number from the orange sim to my new O2 sim on the O2 website?

Itunes Is making me restore my iphone

My iphone 5 is brand new, i plugged it into my computer for the second time to sync the music and it is asking me to restore my phone even though i see no problem with the phone? I'm worried if i restore my settings i will loose all my stuff?