Four Great Gnome Panel Applets
Gnome is the most popular Linux desktop environment and one of it's key features that makes it so wonderful is the "gnome panel". For those unfamiliar the "gnome panel" is the bar that is typically located at the bottom (and top sometimes) of the screen where your menu, task-bar, and icon tray are located. If you have never done it, try right clicking on some blank space and click "add to panel". You will be presented with a list of applets you can add to the panel. While there are a good number to choose from by default, there are piles of other applets you can find online to install. The following is a list of my four favorites I use on my various Linux systems around my house.
Namebar allows you to optimize screen space when you maximize an application by moving the title bar and minimize/maximize/close buttons onto the gnome panel. Download the Namebar in .deb form from here. Also note that you will need to make a small edit to your compiz settings to have it properly remove the gtk bar when maximized.