(1) be sure to place the downloaded files under /photoshop_root/plug-ins/panels/new-folder/. then restart ps & find it under “windows” > “extenstions”. Be aware that this is not a final version & only works in ps cs4.
GridCalc – GridCalc – A visual grid calculator and Blueprint CSS generator
GridCalc takes the pain and guesswork out of calculating a grid that fits your needs. Enter the width of your page, an approximate range for your column and gutter width and GridCalc calculates all the possible combinations and presents them visually. Once you have found a combination that fits your needs GridCalc can generate the Blueprint CSS for version 0.8, 0.9, 0.9.1 and 1.0.