Want to take screenshots of your BeOS screensavers in action? The act of hitting PrintScreen disables the screensaver, making this impossible, but there’s a workaround:
Download a copy of Chris Herborth’s Grab and install it in ~/config/bin. Launch the ScreenSavers preferences panel and select the saver you want to shoot.
Now open a Terminal and type:

sleep 5; grab -o ~/saver.tga 

replacing 5 with the number of seconds you want to wait and using the actual path and filename you want output. Minimize the Terminal window and press the Test button in the ScreenSavers panel.