Personal digital assistant

A PDA is a Personal Digital Assistant. It is used to keep schedules, get on the internet, possibly make calls, and so forth. Technologically advanced PDAs, like Jack Bauer's Palm Treo 650 is able to receive and send messages, pictures, and more. Chloe O'Brian was able to tap into it and send out a certain frequency, causing a bomb to go off. It is very useful in any case, especially in the case of Jack Bauer.