We went a few months without a phone, after Katrina, and only used cell phones, but with two kids and a husband, it seemed like we were always missing each other, or someone's phone was dead.
We spend a fortune on our phone bills. 3 cell phones on a family plan - plus a regular phone that my husband uses to call Yugoslavia (thank goodness for phone cards - any International call is almost free with phone cards!), and our DSL.
One of us needs a separate job just for phones.