A configurable loading spinner that’s smaller than an animated gif, built purely with JavaScript and CSS.
CSS
LESS.app For Mac OS X
An app that autocompiles .less files into CSS. I like this idea much more than having JS do the work on the front-end, or for that matter, having the server-side scripting language like PHP or Python compile it.
Golden Grid System
A “folding” grid for responsive design. An interesting solution to accomodate the use of grids within responsive Web designs. Now to think up a new project to try it out…
Re-tabulate
A great breakdown on how to switch the order that the content and navigation is displayed based on the browser size, using CSS. A key component to truly responsive Web sites and apps.
39 Ridiculous Things To Do With CSS3 Box Shadows
Some are silly, but others spark some great ideas.
Prefixr
Paste your CSS into Prefixr and it will automatically add vendor prefixes for CSS3 properties. Even better, there’s an API available, so you can automate the change or hook into it from your favorite IDE.