I want to change phones. How do I know what phones will fit my sim card in it?

I am so confused. I wanna get a newer model phone but I want to just put my sim card in it. I have pre paid and I want to keep everything the same just change the phone. Thank you for all that help!!!!I want to change phones. How do I know what phones will fit my sim card in it?
umm ne phone that has a sim card will work verizon has NO sim card thoI want to change phones. How do I know what phones will fit my sim card in it?
Any unlocked GSM phone with the same Frequancy as your wireless carrier. Cingular is 850, T-Mobile is 1900.



http://wirelessconsultant.net/unlocked_p