I take a lot of screenshots of web pages, which often have a main section and a background. What I can never seem to do right is crop it in a way that the same amount of background borders both the left & right sides. Just doing it by eye, it is always
uneven. And for the most part, I don't really care. But every once in awhile, it's not for a forum post, and is actually for something that it matters how it looks. For this type of work, rulers would be very useful while cropping. (and for the OCD type of user, they may use it more than I would)
Example of unevenly cropped screenshot:
I also like the idea of a customizable grid, for sizing and positioning clipart. But if you are going to do that, in addition to being able to set the spacing of the grid lines, don't forget to give us control over the color, too.
Now, I am not saying I want you to add the rulers to sc, since I have stand-alone rulers to do this stuff if I really want to (I am usually just too lazy to use them
). I just figured I'd chime in with a use case for you to consider, that could pop up quite frequently among sc users.