If you are an RWD (Responsive Web Design) developer this Responsive Inspector is one of the best tool I came across to inspect the media queries. If you are dealing with media queries daily and test your website in various resolutions and grabbing the snapshot etc. then Responsive Inspector will actually do your job very simple and easy.
Switching between different resolutions min-width or max-width you set in your media queries specified in CSS stylesheets and quickly looking at the CSS you wrote for those particular media queries, taking a snapshot in any resolution etc. is all possible with this cool tiny Google Chrome extension, which is still in beta so giving feedback to the developers would always help them to bring the best RWD tool for you.
The following are few features about this tool:
– Pixel perfect browser resizing to any resolution
– Taking and saving whole page screenshots
– CSS media query code viewing
– Sharing your responsive web design layout on Behance.net service as Work In Progress