annoyme is a program that plays a sound effect every time you hit a key on your keyboard to give you the feeling you are using a real typewriter. This can be used to impress colleagues with your typing skills or just for sentimental reasons. It supports various sound input methods, as well as multiple output libraries like ALSA or AO. Most importantly, it is also possible to add more sound themes. Currently, only input for XEvIE (on an X Server) is supported.
Bitfighter is a game that feels a little like Asteroids on steroids. It's a multiplayer space-based combat and strategy game, featuring customized ships, multiple game modes, cool retro graphics, and smooth network play. It also includes a full featured level editor, Lua scriptable bots, and other cool features. It has a very active development team, so the game keeps improving.