There are many options for what to do with an old cell phone. While cell phones are specific to the service provider, an old number can be removed from a phone and a new number put on it.
If your phone is from one of our preferred vendors, Nextel or Verizon, find out if anyone else in your department needs a cell phone from that vendor. Departmental AO's may wish to hold onto deactivated cell phones from preferred vendors to serve as backup for lost or broken phones, or for staff who need a new phone.
If you cannot identify a business need for your old cell phone, you may consider donating it; see Disposal of Cell Phones