A high-level cross-protocol url-grabber

 urlgrabber dramatically simplifies the fetching of files. It is designed to
 be used in programs that need common (but not necessarily simple)
 url-fetching features. This package provides both a binary and a module, both
 of the name urlgrabber.
 .
 It supports identical behavior for http://, ftp:// and file:/// URIs. It
 provides HTTP keepalive, byte ranges, regets, progress meters, throttling,
 retries, access to authenticated http/ftp servers, and proxies. Additionally
 it has the ability to treat a list of mirrors as a single source and to
 automatically switch mirrors if there is a failure.