Finder
Batch Spotlight Comments - Files
Select multiple Finder files and you can add the same Spotlight comment to all of the files with this application.
Automator Workflow
Step 1: Ask for Finder Items
- Start at: Select Desktop
- Type: Select Files
- Check Allow Multiple Selection
Step 2: Set Spotlight Comments for Finder Items
- Check Append to existing comments
- If you want to be able to change the above option when the application is run, check Show this action when the workflow runs