You can use the SIM Card method for GSM carriers, or find a way to switch plans with the dual-antenna iPhone 4S.
If it's already locked on their network - yes. If it's on another carrier's network - no.
I am pretty sure that all American carriers selling the iPhone use monthly plans for data, text, and minutes.
The monthly cost of an iPhone 6 will vary based on the carrier you use.
From iPhone 4 and beyond you can use simple software to unlock your phone. The 3GS is not able to unlock your phone unless you buy a special SIM card or take it to a different carrier
this depends on the carrier you will be using. the talking and texting part is about the same on att and verizon (~$50). what will vary is the Data. this will be different from carrier to carrier depending on how much you wish to pay for. sprint has their Unlimited everything plan for $70 a month i believe. an iphone 4s will work with sprint in this plan. please keep in mind that the iphone 4s is not a 4g phone on ANY carrier
If your SIM card is not working in your iPhone 3G, you should check with the dealer you got the phone from. It may need to be unlocked for use with a different carrier.
AT&T. But you can "unlock" an iPhone for verizon.
In theory, yes. T-Mobile is actually the carrier for the iPhone in Germany. Keep in mind, however, that unlocking an iPhone completely voids its warranty, and if anything happens to it, the only recourse is to purchase a new iPhone. Apple will not service a broken iPhone if it is unlocked.
I really don't know but I wouldn't think so unless your carrier would let you.
An Apple iPhone 3GS can be purcased unlocked without a SIM card and used with a local carrier's SIM card. Once purchased it is as simple as inserting a SIM card from the carrier of your choice.
Yes. Vodaphone now sells the iPhone.
Not anymore than ks to SIM Cards and the 4S's dual-antenna ability.