The Shapes of CSS
by Chris Coyier
I made a page with the shapes you can make with a single HTML element and CSS. Here is an example:
View Demo Download Files
The CSS you see on the page is the real CSS rendering that shape, and it also editable, so feel free to tweak it right there. I'd love to expand it if anyone has more ideas!
*May or may not contain any actual "CSS" or "Tricks".