Online CSS optimizer tool
When you decide to optimize your CSS file, you can choose “Optimize CSS via URI” (online file), “Optimize CSS via File Upload” (CSS from your computer) or “Optimize CSS via Direct Input” (by copy/paste file into an online form). You can also choose if you want a CSS optimizer to remove line breaks in your file or not.
Firebug-webmasters a must tool
With a click on an element, you will see the CSS source, and you can edit and preview it. Very useful is that Firebug gives you info on what line is that particular CSS element. Imagine working with more than 1.000 lines of CSS code. This can save lots of time searching for mistakes. Firebug also includes a powerful JavaScript debugger. It lets you pause execution at any time and have a look at the code.
Seomoz SEO tools collection
TermExtractor analyzes the content of a given page and extracts the terms that seem to be targeted at search engines. CrawlTest discovers the problems search engine bots run into while crawling your website. The HTTP response codes your page return, cache dates, title tags and much more. GeoTarget determines how well a site is targeted to region-specific search engines.