notification-thing is a full-featured implementation of the Desktop Notifications Specification. It is not tied to any specific desktop environment, and is focused on features like rate-limiting and flexible filtering to minimize distraction and noise ratio in a transparent way, without silently dropping anything ever.
Privacy Manager for Zeitgeist is a graphical user interface which lets you easily control what gets logged by Zeitgeist. It supports setting up blacklists according to several criteria (such as application or file types), temporarily stopping all logging, and deleting recent events.
Voody Blue Subtitler is a suit of programs that allows you to manually synchronize a text file with a video stream, thus creating a subtitles file. It consists of a master client (to do the sync), a slave client (projector), a relay server, and a configuration utility. It runs on Linux and Windows (all except the relay server), supports video output via GStreamer (Linux and Windows) and MPlayer (on Linux only), and supports GTK+ 2 and 3 (decided at compile time).
Screen Message displays a given multi-line message as large as possible, fullscreen and black on white. You can specify the text when launching sm, or edit it while the program is running. It is useful to send messages across a room (e.g., during a university lecture). For fast startup, it is recommended that you bind it to a key in your Desktop Environment.