Connect your iPod to the connections hidden behind the little plastic cover found in the top right, just below the controls. Just pull the plastic cover off.
Press LIST and cycle through until you see CAMERA on the display. Press GO and tada! It works (hopefully)
If your Beo4 never shows CAMERA, then press STANDBY and LIST at the same time, and cycle through until you see ADD?. Press GO and cycle through until you find the function you want to add, in this case CAMERA, and press GO.