We have cell phones only. One nice thing is that I only have one number to give out to people. I think it makes a person easier to reach in that way. One phone number for home, work, and play. (Of course being easier to reach can also be a negative. But if I don't want to talk to that person at that moment, I just don't answer.)
The negative is that now there's people I don't talk to as often. For example, if my husband's sister calls, she will call his cell phone, which he of course will answer. With a land line, either one of us would answer, and you get to know your spouse's friends, coworkers, etc. better.