Yes the iPhone 4 uses whats called a micro sim card it is smaller then the regular sim card out there. At www. phonetraderonline.com they can custom cut your existing sim card or provide you with a micro sim for your carrier.
Not really. They do require different SIM Cards based on model though. The iPhones 2G,3G, and 3GS use Mini SIM, the iPhone 4/4S use Micro SIM and the iPhone 5 uses Nano SIM.
the iphone has a sim card which slots in the top of the iphone. to get the sim card tray out you have to use a pin or the special tool it came with to open it.
AT&T SIM card is needed or if jailbroken/unlocked you can use T-MOBILE
Either apple or at&t because you need a special sim card
Of course, the iPhone 3G and/or the original iPhone will take any normal sim card; the 3G iPhone will take the 3G sim as well.
all iphones have a sim slot but on the original iphone the customer cannot easily access it whereas the 3G iphone has the sim card and a sim card ejector tool How can I access my verizon iphone 4 sim card slot that doesn't have a sim tray
Iphone uses sim cards to track the user and gets all hidden information from them
Then just get an iPod touch ..
You can fit a SIM card from your HTC Wildfire to an iPhone 4 by using the SIM port included in the iPhone.
You will be able to get the services in a Bell iPhone if you use a Komondo SIM card.
You can use the same SIM card for your iPhone 6 that you used in your iPhone 5.
In some situations, the status bar on your iPhone might display No SIM, even though your iPhone has a SIM card.
No sim cards are only for numbers