The first is GeekTool, a preference pane that allows you to display files, images and shell scripts on the Desktop. The second is iCalBuddy, a command line utility that lets you access events and to do items without having to open iCal. Download GeekTool from here and install it by double-clicking on the preference pane. You can now access it by going to System Preferences and looking in the bottom row.
A free GeekTool like application that displays shell output and more directly on your desktopLove to live in command line, but also like to take the mouse out for a spin every once in a while?