Homebrew dev NDT has released a program that can extract the PUP files used to update the Sony PlayStation 3 console. Those interested in taking a closer look at PS3 firmware updates will probably find this useful, although the dev does state that it's more of a programming exercise.
The program is called PS3 PUP Extractor and it's currently at version 1.00. There are already a couple of PUP extractors readily available to the PS3 homebrew community, but according to NDT, what sets PUP Extractor apart is that it can "generate files SHA1 and extract the image version of the PUP".
The archive doesn't include a readme, so we recommend checking out the source link (http://ps3news.com/PS3Dev/ps3-pup-extractor-v1-00-yet-another-pup-extractor-released/) if you have any questions regarding this app.