It has been a long history of download managers on the web and there are quite a few of them out there these days. Some are free, some are less free and some have built in games just to make people pay for it. I remember back in my college days downloading bigger files and splitting them into floppy discs. The internet speed was not that great but the files started to grow. At that time I did not know much of the alternatives to GetRight. It was a great tool and it did the job -- resumed downloads, autodialed modem, shut down the computer.
These days for most of the users the idea is still the same -- download a group of files and resume if something goes wrong. In the broadband times it does not happen very often but it is a nice feeling to know that those files will be downloaded safely.
Since the day the first free download managers came to the scene, I have tried quite a few of them. I believe only Opera has put something similar to the download manager into their browser but I am with Firefox these days.
So, after giving up on FlashGet (it turned out to be quite buggy on my Vista x64), and not really finding anything suitable for native 64 bit support, I have found a plugin for Firefox called DownThemAll that does almost everything that I need (except for the speed control) so if you are a firefox user, take a look, you will not be disappointed.