Two-thirds of U.S. households now have at least one cell phone, and for many, one isn't enough, according to a study from Forrester Research. The number of households with four or more phones has grown by 57 percent over the last year. The embrace of mobile phones shouldn't be confused with enthusiasm for service providers, however. Though carriers are working to improve their networks and customer service, <A HREF="http://news.zdnet.com/2100-1035_22-5669525.html?tag=zdnn.alert">customer satisfaction has declined</A> over the past three years and hovers around 50 percent in key categories.