Can there be a cell phone that takes in and works with 2 or more different cards from 2 fonecompanies?

i mean to use such cell phone with 2 to 5 cards from as many different phone companies.thank you for your answer.

Can there be a cell phone that takes in and works with 2 or more different cards from 2 fonecompanies?
Most of the newer model cell phones currently on the market contain a SIM card that links that phone to your account with the company. If you and your friend both have Cingular, and both of your cell phones have SIM cards in them, you could switch out the cards in the phones so that your friend's phone will work off your Cingular account, and vice versa. However, cell phones are set with a security feature that prevents SIM cards from other cell phone companies from working. For example, if you have Cingular and your friend has T-Mobile, and you switch out your SIM cards, then neither phone would work. I believe they do this as an incentive to keep people from switching to another company. Since you would have to purchase a completely new phone in order to switch companies most people would rather stick the with cell phone company they already have. To answer your question, it is possible to use a single cell phone with multiple SIM cards, and thus having multiple phone numbers with just one phone. However, since only one SIM card can be used at a time it would not be possible to have both lines operational at the same time. However, it is not possible to use multiple SIM cards from different phone companies with a single phone. Even though many carriers offer exactly the same model phones, each carrier puts a security feature into their model that prevents their competition from being able to successfully operate their phone.