If you're looking at creating a responsive website, a good tool to help in this task is unsemantic, which is available online at http://unsemantic.com/demo-responsive. This is a grid system that is very similar to 960, but instead of being a fixed grid, this system has a fluid grid. Instead of being defined over a fixed number of columns, the fluid grid is entirely based on percentages, allowing the layout to adapt to the device viewport and provide a responsive experience to the user.