flypper is a small Python program to implement X11 screen edge flippers. These are 1 pixel-thick invisible strips along your screen edges that allow you to "flip" between viewports/desktops by just pushing your mouse up against the screen edge, or clicking it, or while moving a window up against it, or whatever you want. You can configure them for basically any use, such as popping up a window that says "you are a chocolate dumpling" when you click on the right screen edge.
(Work in progress)