Nicht neu, aber nett:
Did you know you can make triangles with pure CSS? It’s pretty easy. You just make a block level element with zero width and height, a colored border on one side, and transparent borders on the two adjacent sides. They are fun for all kinds of things, like little arrow sticking out from speech bubbles, navigation pointers, and more. Often times these are just visual flourishes, undeserving of dedicated markup. Fortunately, pseduo elements are often a perfect fit. That is, using :before, :after, or both to create these block level elements and place the triangle. One neat use that came to mind in this vein: breadcrumb navigation.
