DistroWatch has a bittorrent link to the new Knoppix 4.0 DVD released a few days ago at LinuxTag. Note that this defaults to German, so use the lang=us switch for English, and be aware that the official release may differ from this one.
Update: the Knoppix.net forums have more bittorrent links.
Also, screenshots (because 4 Gigs takes a while to download).