Bookmarklet: MRI

MRI is a bookmarklet for Internet Explorer 6+, and Webkit and Mozilla based browsers (including Safari, Firefox, Camino or Mozilla). Use it to test and play with selectors.

MRI helps you create the best possible selectors for your CSS. Add MRI to your bookmarks bar, then for any page, click an element, and MRI suggests selectors for that element. You can also test selectors with it.

MRI also uses lots of cool CSS3 features like border-radius, opacity, box and text shadow, as well as the HTML5 canvas.

Bookmark: Bookmarkme

Source: www.westciv.com