In autocad there is a command called offset. Eg. you draw a vertical line and want three more at ten foot intervals. You select 'offset' and input 10 feet, click on the line and then click on the side of the original line you want the new one and then do that 2 more times. I would like to see such a command with the guides and be able to offset in both inches and pixels. I would also like to see the ability to slope the guides as an aid to placing parts of other photos and aligning them.