Let’s say you spent your vacation abroad a couple of years ago. Being thrifty, you removed your U.S. SIM card from your unlocked iPhone 4 and inserted a SIM card from a carrier in the country you were ...

The subscriber identity module -- SIM -- contains the information used to connect to your wireless carrier's network from your iPhone 4. If you are planning to resell your company's iPhones, you ...

Running a business requires you to stay connected to the outside world, and one way to do that is by having a smartphone. IPhones are often used for this purpose, but they are useless if you can't get ...