This is a new irregular feature here at The Genealogue. Let's define a "genealogy hack" as a tip or trick that solves a specific problem and increases one's productivity as a genealogist, whether online or out in the real world.
Ever try to bookmark a manifest page from the Ellis Island website using your right mouse button? If so, this will look familiar:
Saving the manifest image in Firefox is simple using this technique. From the menu that pops up select View Page Info > Media. Then click on the entry that looks like this: