Grid-based layouts have become really popular among web designers over the last year. This popularity is due largely in part to the work of Khoi Vinh, Design Director of NYTimes.com. So, GridFox is a Firefox extension that overlays a grid on any website. If you can open it in Firefox, you can put a grid on top of it. It’s easy to customize, allowing you to create the exact grid you designed your layout around.

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