When you take pictures of copy image files to your S60 device, they will be appeared in the Gallery application. In some case, you don’t want to appear them. What should you do? The answer is set the file attribute to "hidden".
In order to do that, you need a file manager is capable of browsing to all folders. Unfortunately the default S60′s file manager won’t do the job. You need a more powerful one, for example Y-Browser.
After downloading and installing Y-Browser, run it, select your image and select Options | File | Attributes menu. Set "Hidden" field to "Yes".