good ideas carol - i was thinking to add a command to copy the current selection and auto save it as a new image file in the screenshot directory, which would do what you say.
and you gave me a good idea to support dropping image files into clipart panel to copy them into clipart directory.
it think your resize idea is a good one - might be a little hard to do it exactly as you suggestion, but i think i might be able to come up with something close. an easy temporary fix of course is to just select resize dialog, enter a large value in upper right box, and let it grow entire space around the image, and then crop to desired size by eye.