It’s worth all the attention it’s getting. It makes working with CSS selectors, and especially scraping websites, dead simple. This is the gateway into
The kind of information that it gives you can be fed into jQuery (or other CSS selector aware API’s like nokogiri or hpricot for Ruby or beautiful soup for Python) to easily get the right syntax for querying the DOM.
Check out the author’s screencast on the front page. He very quickly demonstrates how easy it is to use SelectorGadget to modify the scope of the intended selector.
P.S. if anyone is aware of any Groovy/Java parsers that can take CSS 3 selectors, I’d love to hear about them. Some quick googling isn’t showing anything.