Can I have one number on two phones?

I have a PPC-6700, but it’s too big to carry all the time. Most of the time I need it, but I’d like to buy a smaller one as well. So I’m wondering if it’s possible to reprogram another phone to use the same MSID and MDN?

You can do this via ESN switching, although you won’t be able to turn them on simultaneously. All you have to do is call a CS number and they’ll switch it for you to the other phone. It normally is done instantly for voice. Just in weekends it takes about 5 minutes or so.