Hmm, I hadn't thought of putting it there. I'll have to think about that, it's a neat idea. My original plan was to add per-column settings, a little button next to the X to close columns, with additional filtering options. But this might be a good way too and allows you to do it instantly without having to first create a column. Actually, I guess I could reuse the add column dialog as a column settings dialog too, by just prefilling it with the current settings of the column.