I'm subscribing because I am also interested.
Whenever possible, I use d4x (Downloader for X). That's a gem but, of course, you need a link to the file and javascript download "links" cannot be copied.
That app is moving to another site but you can still get downloads, I believe, at
http://www.krasu.ru/soft/chuchelo/ I installed my distro's version for some reason I've now forgotten.
EDIT: BTW, I have looked up Flashgot. It isn't a download manager; it's a plugin to let you use other download managers with Firefox. I'm hoping it will force Firefox to use d4x on my system. You may also want to look at this:
http://en.wikipedia.org/wiki/Compari...nload_managers