Mobile telephone technology has been rapidly embraced across the globe. Mobile handsets have been used in several medical and health studies, but have been explored much less in cognitive behavioural therapy (CBT) research. This paper describes the advantages of mobile telephones as a tool to assist psychotherapy and psychotherapy research, as well as new capabilities that have emerged over the past two years. The advanced technology of mobile telephone handsets allows for numerous applications that may be beneficial in CBT, as well as integration with existing technologies such as the internet and handheld computers.