I have a task where I need to display a long list of categories (variable number). Underneath each category is a list of subcategories (once again variable number). Now I could just have a single column of this information that will force the user to scroll down to see them all. Instead I would like to utilize the empty real estate and perhaps have a set of three or so columns that allow the list of categories to fill out the rest of the page.
I also don't want it to be "griddy" (hey i think i invented a word there!). A category may have one subcategory while another may have fifteen. I don't want an ugly whitespace separating the single category with another category below it just b/c the category to the right of it (the one with fifteen is long). Any ideas on how I could best approach this - either some css or just some general advice?