(Nobody mentioned this yet, so I figured I would ...)

The Info-Zip group has finally released Unzip 6.0 (> 2 GB files, Bzip2 compression, Unicode) on April 30, 2009. (This is the companion to the recently-released Zip 3.0.)

http://www.info-zip.org

ftp://ftp.info-zip.org/pub/infozip/src/

ftp://ftp.info-zip.org/pub/infozip/win32/
ftp://ftp.info-zip.org/pub/infozip/msdos/

(Seems to lack other prebuilt binaries so far, but it's easy to compile.)