Turns out it's pretty inconvenient to use only a cellphone for communications to the world. It doesn't ring loudly enough to be heard at the other end of the house, and reception here is much worse than in Tampa. For example, we have to stay in the front of the house in order to use it; if we're in the back (where the computers are), it'll spontaneously lose connection. Which is a little bit inconvenient, if you ask me.
So, after reading Squelch's post about getting voice-over-IP, and asking him a few questions about how it worked, we decided to sign up for it. Using our high-speed Internet connection, we can get local and long-distance phone service (using real phones from any existing jack in the house, not just sitting in front of the computer) for only a fraction of what we were paying the phone company. And by "a fraction", I mean less than a tenth of what we were paying every month.
Unfortunately, they were out of Tallahassee-area phone numbers, so we'll be using an 813 area code (so all our friends back in Tampa can call us as though we were local), and for $5 extra per month, I got a second, toll-free number so we're not a long-distance call for someone living next door to us. (When an 850 area code number frees up, I'll probably do some shuffling.) If we lose our Internet connection, it'll automatically forward calls to our cellphone.
Pretty nifty. (At least until the phone companies lobby Congress to put a stop to this flagrant lack of price-gouging.) Now to wait until the equipment arrives, to see how well it works.