Rated 5 out of 5 stars
If you use patchy or slow internet connections, or occasionally need to download very large files, you are probably already familiar with download agents like wget and cURL that can restart failed downloads where they left off. This great add-on enables you to use the same tools with downloads that require some browser interaction (such as a password) in order to access the file.
To restart a failed download, add "-C -" (without quotes) to the end of the cURL command, or "-c" to the end of the wget one.
Do consider the security implications if you're downloading to a shared server, though.