Ask the select[or]racle

This is a nice tool, which translates you CSS selector syntax:  selectorracle. The site says:

Ever wondered what a particularly complex CSS selector really means? Here’s your chance to find out! Simply enter one or more semi-colon separated selectors or rulesets into the following “Direct Input” area, or provide the URL of a stylesheet in the “URL Input” area. Best of all, the SelectORacle will flag potential errors and other problems, and it won’t choke on any actual rules. You’ve always wanted to know what makes those line-noise posers tick– now you can.

http://gallery.theopalgroup.com/selectoracle/