When I have a picture open and I select "PROPERTIES" and check the HIDDEN box, where do they go? I cannot find them!::
The file is still on your device until you delete it. If you use a storage card, then it would be on it under /Media Card/Blackberry/pictures. Just go to that folder and select show all from the menu to see it again.
I do not have a memory card though! Where might they go then?
They are still in the main memory. You can find them under the same file hierarchy as I described in the main menu. You can also go into your pictures album on your device and press the Menu button and press Show all.