not really, but you can set the prefix and form of file names, and you can easily rename any image by simply selecting it in the window, typing the new name and hitting enter. the focus of screenshot captor is to help you take a bunch of screenshots and work with them so one usually doesnt want to name files until you have taken several.
however, it's not a bad idea to add an option to ask user the name at time of capture - i will add an option for that to the todo list.
