I dropped my landline about 5 years ago and haven't looked back. I have Verizon Wireless and have found very few places where I can't get a signal. I also make sure to have the phone charged regularly, though my particular phone will hold a charge for several days without dying.
By dropping the landline I rarely used, I cut my "telephone" expenses more than in half.
During the recent Maine earthquake, my niece and I could not make phone calls (same carrier) because the relay was overloaded with calls, however I was still able to text my sister and make sure everyone was OK.