PDAs can be used to provide their users with a variety of functions. One function provided by PDAs is enabling their users to contact particular users of other devices who are stored as contacts, for example by a telephone call or text message. The present invention provides a PDA in which contacts that the user of the PDA may be more likely to want to contact at any given time can be determined and displayed. Whether or not a user may be likely to want to contact a user at any given time may be based on the status of the user of the PDA, and optionally also the status of the other user's PDA. For example, if the user of the PDA is listening to a particular genre of music, then they may want to contact other contacts who a also listening to that particular genre of music. Similarly, if the user is at their place of work, then they may want to contact a specific list of contacts related to work. In this way, the user of the PDA can be provided with a list of relevant contacts.