1stwebdesigner: 20 snippets you should be using from HTML5 Boilerplate
Sounds stupid and listy but it's actually a good introduction to some of the more useful and practical pieces of the huge insane HTML5 Boilerplate (html5boilerplate.com).
GitHub: Scaling Background by Justin Ouellette
As seen on Normative.com.
Shaun Inman: Styling File Inputs with CSS and the DOM
Ugly "Browse..." buttons be gone!