KBiff is a KDE "biff" or new mail notification utility. It is highly configurable but very easy to use and setup. It supports session managment (it "remembers" the last state it was in before you logged off) and can be docked into the panel. It has support for mbox (Unix-style), maildir (qmail-style), mh, POP3, IMAP4, and NNTP mailboxes.
K3b is a CD and DVD burning application for Linux systems optimized for KDE. It provides a comfortable user interface to perform most CD/DVD burning tasks, such as creating an audio CD from a set of audio files or copying a CD. While the experienced user can influence all steps of the burning process, the beginner may find comfort in the automatic settings and the reasonable defaults which allow a quick start. The actual burning is done by the command line utilities cdrecord, cdrdao, and growisofs.
Actualiza is a semi-automatic update program for apt-based systems. With a simple GUI, this apt front-end lets you manage the programs / components on your computer, and helps you to keep it updated by showing the available updates by means of an applet. It features a powerful progressive search engine, and a repository manager that allows you to add or remove repositories easily.
vlock is a program to lock one or more sessions on the Linux console. This is especially useful for Linux machines which have multiple users with access to the console. One user may lock his or her session(s) while still allowing other users to use the system on other virtual consoles. If desired, the entire console may be locked and virtual console switching disabled.