Another idea
We had noticed that we only get solicitations on the home line, and very occasionally the reminder call for doctor and dentist appointments.
About a month ago, I ported our home line to
http://www.parknblend.com -- at which you can either get voicemail (which it will email to you in a .wav file, or text your cell, or send you email ... whatever you like), or it will forward to another number. The plan is to try this for six months and see how it works. If all goes well, I'll drop it entirely.
The message on ParknBlend announces that we're ending this number in summer 2012, so please get in touch with us via our cell number, email, fax, or postal mail (but doesn't give out any of these). In the month, we've had two messages left.
Meanwhile, I have Skype's new freecall gadget providing us outgoing dial tone. It's OK but not terrific. I first tried the new MagicJack plus. That had OK quality, but would not permit us to hide or spoof our caller ID. With Skype, you don't have a number unless you buy one, and you can spool a cell phone number that belongs to you. If the quality continues to disappoint, I may try Ooma.