I have a suggestion for downloading...
Jigdo or Jigsaw Download
http://atterer.net/jigdo/
I recently downloaded the full Debian Release (Linux)
about 23 gigs. (yes 23 GIGABYTES) 5 DVDs
Jigdo increased my download speed by a factor of about 7.
Not only did it download the ISO image in pieces but did a
verification and checksum while rebuilding.
Another factor to consider when downloading HUGE files
is your source or mirror will most likely impose bandwidth
restrictions on you as your download uses too much bandwidth.
When this happens, we normally see our download slow down
and level off at a reduced speed. (not so with Jigdo)
Still kind of obscure, but has great potential for ISO images and such.