Download them all is a extension for firefox that lets you download everything on the current page by right clicking and clicking on downloadthemall. The plugin is fairly easy to use with some great settings. You can choose whether you want to download pictures, videos, mp3.
Downloadthemall is especially great if you come to a site that has lots of things you want to download but you dont feel like making a big mission. Just right click on the thing and download them all.
Download them all has been around for some time now and its still one of the most downloaded extensions out there. Its worth giving a shot if you regularly download stuff with Firefox. Especially on image sites.A page with 100′s of images can be downloaded with two clicks. Download here