I put Magic Jack in a couple of months ago.  I took the $99 for two year 
plan.  I think the receive audio is a bit soft, but it isn't worse than tyme 
warner phone, and for the price, I can't complain.

Sometimes I loose the connection and have to redial after an hour long 
conversation.  I think the major variable is the quality of your Internet 
connection.

Free directory assistence for everybody is a good thing.
You can keep your own number.  You have to dial the full number including 
the area code for every call.