Emergency Program One
Emergency Program One was a feature of the Doctor's TARDIS designed to return a companion to a designated place in case of extreme emergency. (TV: The Parting of the Ways)
The Tenth Doctor mentioned that Emergency Program One was automatically activated after five hours. (TV: Silence in the Library) When activated, it projected a hologram recording which explained the program. (TV: The Parting of the Ways)
The program was tripped by the Tenth Doctor when he tried to get Majenta Pryce to Panacea. It was then co-opted by Finn Dargo, who used it as a way to effect an arrest on the TARDIS' inhabitants. (COMIC: The Crimson Hand)
Believing that he would die on the Game Station, the Ninth Doctor used it to play a message for the benefit of Rose Tyler before the TARDIS returned Rose to her home of Powell Estate in 2006. (TV: The Parting of the Ways)
Donna Noble recorded a message on it as a way to say goodbye to the Tenth Doctor, in the event that she might not have a chance to do so herself. (COMIC: The Time of My Life)
Security Protocol 712 seemed to use the same holotechnology as Emergency Program One. (TV: Blink)