Sometimes it can be useful to know how big the browser window is so you can test breakpoints.
It can also be useful if you want to see how a website designer has chosen to switch designs at given pixel breaks.
Or it might not be at all useful.
Here's your browser window tape measure: http://howbigismybrowser.com/
Open it in a tab, open another website in another tab and play with the width seeing how the design changes. You can see the actual browser size just by changing tabs.
OK, it's a simple thing, but I think it's cool.
Paul
