min-device-pixel-ratio test
What’s your device’s min-device-pixel-ratio?
Techniques For Gracefully Degrading Media Queries
Responsive Web Design: Helpful Articles, Techniques & Tutorials
A Beautiful Boilerplate for Responsive, Mobile-Friendly Development
Adactio: Journal—Sea change
Responsive design
Here’s what we’ve learned about doing UI for mobile web apps with WebKit - (37signals)
A couple of useful tips on fonts and form elements
10 tips for designing mobile websites | These Days Labs