Poly, the $250 deal is something called Ooma. i bought it last month and my number gets ported on Tuesday according to the email i received. i'll go from paying AT&T $62/month for local and long distance to $0. i pay Ooma $0/month. in < 5 months the Ooma will have paid for itself. (i am going to subscribe the premium service in Ooma, which is about $12/month after my free 3 months of it are over . . . but it isn't necessary by any stretch). http://www.amazon.com/ooma-Telo-Free-Phone-Service/dp/B002O3W4LE/
i did have to buy a 50' phone cable to run from the Ooma, which gets its phone connection from my cable modem, to the phone box on the outside of my house to replace the AT&T phone cable that comes from outside. this way, all phones and fax machines, etc. in my house work using the Ooma instead of AT&T.
regarding the 911 issue . . . you'd have to check in your area if the E911 service is available
. i think it's pretty standard now in north America. Ooma has it. when i signed up i had to provide the specific address for the number i was registering. when we call 9-1-1 then the address automatically goes to the 911 center as our call arrives. i put off shifting to Ooma (or any VOIP) until i felt like the 911 issue was resolved since it had some problems many years ago. we have our iPhones to make 911 calls as well when we're home and most babysitters we hire have cell phones as well these days. i also have the Ooma attached to a APS battery backup solution in case the electricity goes out.
but back to the original topic . . . (EDIT: and i see macbeemer said much of this now that i completely read the thread) i have Google Voice. i give the number out and have done so for many months now. i typically have calls ring both my iPhone and home phone. if i am home then i'll take it on that phone to avoid wasting cell minutes (same thing if i am at work). my wife calls her mom once or twice a week in Illinois. instead of using the home phone to make the call, we have Google Voice call her mom for us. you click a call button in Google Voice and then select her mom. it asks which phone you'll be talking on. we select our home phone and hit call. immediately, our home phone rings. we answer it and then immediately my wife's mom's phone rings. they can talk all they want and Google pays for the long distance call and nothing appears on our bill. of course, we when switch to Ooma this coming week then i am not sure Google Voice will get as much use. but i do like to use Google Voice when i give online tests to my students. with 70+ students i tend to get a few calls at once. i asks students to enunciate well and leave a message. the message is transcribed and i see it immediately. this saves me time during the test because i can call the student back with the answer right away and also have a record of everything that was problematic to review the next time i give a test.