Having researched various voice-over-IP alternatives, my family and I this week chose Ooma for the bulk of our home phone needs. Ooma makes its money from the $200 initial hardware purchase. After that, there is no monthly charge, only taxes and fees.
As part of the move, we disconnected one line that was dedicated to a fax machine—the machine still works, but so does my last VCR—and switched our more-used landline to a less expensive, local-only plan for emergencies.
We've gained lots of desk space putting our motley crew of phones in storage, and overall we should save $100 per month. Ask again after our next bill.