clipped from: lifehacker.com   

When it comes to heavy duty download jobs, Firefox's default Downloads manager just doesn't cut the mustard. If you often need closer control of multiple, large downloads, you need the DownThemAll! Firefox add-on. This extra-strength download manager can speed up, queue for later, and batch download sets of files from the web based on patterns you define in one click.

Using filters: Download all the MP3's on a page

Define your filter.
dta-mp3-filter.png
Select all the MP3's with your filter.
dta-idolator-mp3s.png
Custom rename files.
dta-rename-tags.png

One-click access to dTa settings

Once you've got a set of dTa preferences set up that you want to reuse over and over again - say, if you want to download several Flickr sets on different pages - you want to use dTaOneClick!, also available on your right-click context menu. From the help:

The one thing you can't do with dTa that you can with my beloved command line wget is schedule regular, recurring downloads (like all the MP3's from Idolator every day at noon).