Extracting PSN store .pkg's

[kevstah2004]

Does anybody know how to extract .pkg's downloaded off the PS3 store?
example

http://zeus.dl.playstation.net/cdn/x/xxxx_xx/xxxxx.pkg?product=xxxx&country=xx

xx:
gb = Great Britain
au = Austria?
at = ???
it = Italy?
es = Spain?
de = Germany?
pt = Portugal?
hk = Hong Kong
jp = Japan
us = America

Uses a program called ps3unpkgr but I can't find it anywhere.

http://www.ps3news.com/PS3Dev/A-Peek-inside-a-PS3-PKG-file/