You can change the report title of the report that you are about to generate. This will not be a permanent change; it will only show up on the report that you are about to create. After you have selected your report from the "Reports" button or from the menu bar, you can rename it while you are setting the parameters. Highlight the existing report name in the "Title" field and type in whatever you would like it to be.
Sometimes the "Title" field is called "Report Title" and sometimes there is not even a heading for the "Title" field (i.e. any of the Data Grid Reports) because it is in an obvious place.
Almost every report gives you the option of naming the report except for those with the word "Labels" in the title.