The phones use a SIM (subscriber identity module) card, which is a thumbnail-size silicon chip that contains a phone's "guts," including its telephone number and list of contact information. The card is usually found behind the phone's battery.
AT&T Wireless and VoiceStream Wireless also sell cell phones that have these chips.
The cards can be removed from one phone and put into any other phone. With the transfer, the new phone assumes the embedded telephone number and can retrieve any other information stored on the card's 64K of memory.
The phones are meant to answer a major complaint from cell phone subscribers: People can't keep their phone number when they change phones. Wireless carriers also like SIM-card phones because the phone itself doesn't need to store as much information to run. That frees up memory to do more things like send wireless e-mails or download graphics, features that carriers can sell to their customers.
SIM cards hit Europe and Asia first, where most of the new cell phone technology has made its debut. But more cards are finding their way into the United States.
Nextel's six previous SIM-card phones use a telephone standard known as Integrated Dispatch Enhanced Network, or IDEN, which enables two-way radio and wireless voice communications.
The two new phones--the P280 and the v60--are based on the GSM (Global System for Mobile Communications) telephone standard. Users of IDEN-based phones will be able to broaden their network access by plugging their SIM card into one of the two new GSM-based phones.
People with an IDEN as well as a GSM-based phone will have a "universal telephone number" and will be able to accessIDEN networks as well as GSM telephone networks.
The P280 costs about $150, while the v60 is priced around $300. Neither cell phone includes the SIM card, which is included with IDEN-based phones.
Before the two new phones came out, Nextel customers could use the phones only in North and South America, said Miguel Lecuona, senior director of marketing at Nextel. "The Motorola P280 and v60 allow our customers to expand their reach, just by swapping a SIM card."