KAlarm lets you schedule personal messages to display, audio files to play, commands to execute, or emails to send. Among its options, it allows you to choose the message font and color, recurrence schedule, whether to display an advance reminder, whether to speak the message or play a sound when it is displayed, and whether to cancel the alarm if it can't be triggered on time (e.g. if you are logged out at the time). As well as using the graphical interface to configure alarms, you can use the command line, and there is a D-Bus/DCOP interface for other applications.
gjots lets you organize text notes in a convenient, hierarchical way. It can be used for notes, jottings, bits and pieces, recipes, and even PINs and passwords, using encryption. It can also be used to "mind-map" larger compositions like manuals, Web pages, articles, etc. It is a bit like the KDE program "kjots", but uses the GTK library and supports a hierarchy of folders. Files can be output to HTML with an automatic table of contents or to docbook XML. Encryption is supported with ccrypt(1), gpg(1), and openssl(1), so that musings can be kept private.