We have three types of phones at home. Mobile phones where we do the bulk of our personal and professional calls, a regular landline for calling local numbers and a VoIP phone for international dialing. According to a study conducted by Harris Interactive, more than half of the consumers in the US who use only a mobile phone as a primary mode of communication are under the age of 30. It was also found that a third of consumers aged 18-29, use only a mobile phone or the internet to make their calls. Mobile phones are fast catching up with landlines, and in the study it was found that more than 8 out of 10 US adults used a landline phone as their primary phone, while more than three-quarters had a mobile phone, and 1 out of six used Internet or VoIP phone systems.