Responsive Web design (RWD) is on the mind of every ‘net worker – from designers and developers, to Internet advertisers and search marketers too.

The benefits of RWD are well documented, but whenever there is a new technology to explore, or even just a new way to do digital work, the tools and resources that make it truly useful (and even fun) are often slow to emerge. But emerge they do.

Case in point is Victor Coulon’s new (and free) RWD Bookmarklet.

With the bookmarklet installed (just drag the link to your browser’s bookmarks bar), visit any website and click the RWD bookmarklet link. A toolbar will then load where designers/developers can select a typical tablet and mobile resolutions and see if the site is responsive or test out new designs to see how well they render on different devices.