How to let user specify name of new screenshot using Automator
After much hunting, I found Get Selected Finder Items and then Rename Finder Items: Name Single Item.  One nuance is that renaming the file ends up recursively calling the script, because the file with the different name is perceived as a new file.  I got around this by having a 'staging' folder, then the ultimate destination folder, and used Mover Finder Items as the last step in my Automator sequence.