Technology Upgrade

I've just discovered that my current cell phone is malfunctioning more than I originally thought. I just thought that, since I've had this phone for so long that the battery was the only part of the phone that was misbehaving so much. NO! I've now figured out that, even if my phone's on, I'm beginning to have difficulty receiving and making calls. I sometimes get a "Welcome to Verizon Wireless" message if I'm trying to make a phone call or check my voicemail. Those clues tell me that my phone is no longer in proper working condition.
I'm glad that my mom's going to get me a new phone- one that's in proper working order- this summer. I might end up having to change my phone's service to Cingular, which wouldn't be too much of a bother. However, I wonder if I'm going to have the same phone number, and if I'll be able to transfer all the information from my current phone into a new one. . . or, if I'll have to re-enter everything.