Everyone seems to be in this CSS 3 madness. Sure, but you should keep in mind, that not every CSS is supported across different browsers. And Can I Use.. is here to help you out.
Compatibility tables for HTML5/CSS3
Whether you fancy CSS3 gradients,
box-shadow or some neat HTML5 tags, Can I Use.. delivers nicely formatted compatibility tables for all major desktop (IE, Firefox, Chrome, Safari, Opera) and mobile browsers (iOS Safari, Opera Mini, Android, Blackberry, Opera Mobile, Chrome and Firefox for Android).
For latest news and additions follow @caniuse on Twitter or subscribe to their RSS.