Update: PKGView BETA 2 Extractor is now available, which includes a few fixes as outlined HERE.
Today ifcaro has released PS3 PKGView BETA 1 and naehrwert has released UnPKG with source code, both are PlayStation 3 PKG file extractors / unpackers.
Download: http://ps3zone.ifcaro.net/archivos/PkgView_BETA1.rar / http://www.file-pasta.com/file/0/unpkg.7z
To quote, roughly translated: PKGView is a file extraction tool to debug PS3 PKG files. This tool 100% legal it contains no code Sony.
PKGView has a graphical interface that simplifies the extraction of both individual files and the complete package.
Note: This version is very limited and only allows you to extract individual files, it can not remove folders or create PKG files.
Finally, UnPKG requires the VC++ Redistributable Package to run the exe file linked above. Props to emot for the news!
More PlayStation 3 News...