Download Manager (S3) - View and manage downloads from a tidy statusbar.
Download Status Bar - Download Status Bar manages every aspect of your downloads (Launch, Show, Scan, Send To, Rename...
Chrome Download Manager - Chrome Download Manager. Bring Google Chrome like Download shelf into Firefox.
Status-4-Evar - That status bar was removed in Firefox 4.0.
JDownloader - JDownloader is a free downloading tool that enables you to download files from over a hundred hosting sites. The tool is compatible with Linux, Mac and Windows operating systems. Read more about JDownloader.
DownThemAll - DownThemAll is a free extension for Firefox that is designed to allow you to download multiple links or files on a page without having to click each link.