How to use an old iPhone again?

My iPhone just broke so I have an iPhone 5 on the way. For the meantime, I want to use my sisters old iPhone 3GS. My old phone was a 3GS as well so I was wondering if there was an easy way if doing this? Thanks

Added (1). Putting my sim card in won't work

Are you serious?

You have got to be kidding.

Put your sim card in the phone you want to use.

Just put the SIM in your sister's iPhone 3GS, simple.

If just putting the sim card in doesn't work means that those phones were locked to a different service provider. Either that or you put it in upside down

  • Will I ever be able to use my iphone again? I've got an iphone stuck in recovery mode loop after trying to update to ios 7 and get error 1669. If I try to downgrade, it gives me 1394. I tried tinyumberella and Ireb, basically everything I could try and it failed. Is there a way to fix it. Will I ever be able to use my iphone again
  • Pics appearing again n again in Iphone even after deletion? Some one has clicked my pics from i Phone. I have also deleted it from his camera roll and photo Stream but still he is able to recall that pic again n again. Person is not using i cloud i have. May be using some kind of app i have no idea. Can somebody help me here?
  • Old iPhone with old sim card? Mum just got a new iPhone, so gave her old one to my sister. My sister did not have an appropriate sized sim card, so they guy at the store cut it down. Mum's new sim card is working, but when we put my sisters in the old phone, it just keeps saying no service. What do we do? Can we use it or not?
  • Just got an iPhone 7, should I use my old earbuds with the dongle/lightning connector or use the ones that came in the box? I'm not sure which I should use first. Use the lightning connector with the earbuds I've been using or should I use the earbuds that come with it that just plug into that charging hole? Sorry I'm not so good at deciding.