The latest English version is:

KNOPPIX_V3.2-2003-07-26-EN.iso

The latest German version is:

KNOPPIX_V3.2-2003-07-26-DE.iso

Use any of the download mirrors. Preferrably an ftp mirror near you but any of them *should* work.

Don't forget to download the md5sum for the same .iso and compare it before you burn your cdrom.