Elijah's Watch journal

 is a Holotape in the Fallout: New Vegas add-on, Old World Blues. It can be found at Elijah's Watch which is located just north of the Securitron De-Construction Plant and just east of the Mysterious Cave.

Explanation
In this note Elijah discusses his last observation post he established at the Big Empty. The first post was located in the Little Yangtze Watchtower. It was here he experimented with the bomb collars worn by Little Yangtze's inhabitants, which he then used to force the Courier along with Dog, Christine, and Dean Domino to free him from the Sierra Madre in the Dead Money add-on. At this post he also noticed for the first time someone watching him. This person turns out to be a Brotherhood of Steel assassin named Christine who had been sent to eliminate Elijah after rampaging through the Mojave. After he leaves this post he moves to another camp atop the Signal Hills Transmitter where he is able to improve his radio connection with the antennae array at the site. Finally he leaves his camp at the Signal Hills Transmitter and moves to the location of Elijah's Watch.