The "Average Joe" gets a new cell phone once every one and a half years.  Everything from lost phones to broken keypads to simply wanting to have the latest and greatest contributes to the high turnover.  Fortunately, this means that people that are looking for great deals on used cell phones can usually get phones that are relatively new to the market.  In fact, in some cases you can find phones that were just released but were returned shortly after being purchased.  Since cell phone technology rarely changes, most people can find a used cell phone with all the features they want at a great price.

However, before buying a used cell phone, you have to make sure that you're shopping for a phone that is compatible with your current network.  There are two different "types" of technology being used on the North American networks - GSM and CDMA.

Phones on GSM networks cannot be used on CDMA networks and, of course, the opposite is also true.  GSM network phones have what is called a SIM card inside of them.  SIM cards are removable and are what identifies the phone with the network.  CDMA phones do not have SIM cards.  When you begin your search for a used cell phone, it is very important to know what kind of network your carrier operates on.  A quick internet search will help you answer that question, or you can look inside the back of your current phone to see if there is a SIM card (usually underneath the battery).

Once you've purchase a used phone for your network, activating it is a breeze.  Here's how:

Phones on a GSM Network are very, very simple to activate.  Simply remove the SIM card from your old phone and place it in the back of the new phone.  Turn the phone on, and you're all set.  If you have problems removing the SIM card or installing the new one, check online - there are several articles and videos for specific phone models.  Alternatively, you can check with your service provider or third party vendor that you bought the phone from.

A SIM Card

If you have lost your old phone and don't have a SIM card to put in your new phone, you'll have to contact your service provider to get a new SIM card.

Phones running on a CDMA Network are identfied by their ESN number which is number that is unique to each phone.  The number is usually found underneath the battery of a phone.  To activate a CDMA phone, you will need to locate the ESN number for both your old phone (if you still have it) and your new phone.  Once you have this information, simply call your wireless provider and they will be able to get the new phone activated for you.

Activating a used phone is much easier than it used to be.  With almost all phones available in the used market, you can find a great deal on a used Blackberry and have a top-notch phone for much less money out of your pocket. Following these simple steps should be all the information you need to be happily using your new phone in no time.