I have two cell phones, one of which stays in the glovebox of my
second vehicle, and never receives calls. I'm tired of having to pay
and pay every month for service for it. I'd love to have it as a
second phone on the same account. Is there any way to do this?

Is "cloning" an option? Would it be legal? I wouldn't be defrauding
anyone as I own both phones (Motorola Star-tac) and I don't see how it
makes any difference to the carrier which handset I happen to use.

Another option I looked into was "pre-paid" but unfortunately it looks
like I'd have to pay every month with that to keep it working, too,
even if I never used the phone.

Any advice appreciated.

Chris