IPhone 3G

IPhone 3G is much higher than the old model iPhone, however, there are still a few things that could be improved.
, Some of the old adapters do not work with 3G

Does not record video
No, voice dialing

Expandable memory, not
There is, however, better features and substantial improvements tothe 3G
Some are designed for the use of mobile phones and subscriber identity module (SIM) card or chip that stores subscriber data. The card is issued by the carrier and provides cell service by activating any phone that is inserted. Phone is locked, however, recognizes only the SIM card of a specific carrier. If unlocked cell phone, it will be recognized on the SIM card from any carrier. "Lock" is the development of programs that keep the cell phone "loyal" to one carrier.
In areas such as the United States, where phone companies offer free or discounted too, with plans cell, and usually is secured so that the phones will not work with other airlines. Claim the airlines and this is essential to support the cost of phones. After a period of time, the carrier may agree to open the phone upon request, and may impose a fee. However, because of the installation settings property in some cases, locked phones, phones do not always work correctly with other airlines, and even an unlocked one.