It seems the only method that works currently (Firefox 7.0.1), is: 1) Drag or rt-click->save as the image to the desktop. 2) (Have iPhoto Preferences->Advanced:Importing:"Copy items into iPhoto Library" checked.) 3) Drag the desktop image onto the iPhoto icon in the dock. iPhoto will create a new event for the image. 4) In iPhoto rename the "event" to be a new "subject event" to hold all images of this type, or merge the event into an existing "subject event" 5) Move desktop image to trash The "it just works" way is to use Safari, right click image, "Save to iPhoto Library" to eliminate steps 2) and 3) above.