I wasn't going to post this anywhere, but after seeing another one here I figured I'd post mine.
This is one of my first apps I made for PSP. It's another directory creator, but it has some cool things on it. It has a menu with all directories listed it can create, it's missing the GAME/UPDATE because I made this on 3.52 M33, and it wasn't used too much then. This was just changed recently to add GAME371. It also has an option to run a script to create user specified directories. Read the readme, it should explain it. The dir.txt has the script in it to create the UPDATE and ISO/VIDEO folders. If you have any questions, feel free to ask. If I forgot anything, please tell.