I'll try this - my concern is that the picture stays available as the 'album cover' when looking at/for music, and that the music in the folder with the album cover picture is still visible.
I'll let you know how that goes...
Can anyone recommend a good app for hiding them?
The '.' Method. Basically you place the pictures you want to hide in a folder and put a . in front of the folder name and the gallery shouldn't show those photos. There are also applications on the market that hide things for you.