SVG Gradient Background Maker
Handy
The ultimate CSS tools for web designers | CSSmatic
Gradient generator, border radius, noise and box shadow
ProtoFluid - HTML5 and CSS3 Web App Prototyping
Test your @media queries and web app on various screen sizes
CSS3 Please! The Cross-Browser CSS3 Rule Generator
You can edit the underlined values in this css file but don't worry about making sure the corresponding values match, that's all done automagically for you.