PS3HaX member $n!pR has updated his PKG Toolkit GUI application:
This is my GUI for the signing tools from geohot. I might expand it to include other tools later. Tested working with the couple apps I made so hopefully it works just as good for anyone else who wants to try it.
NOTE: This requires Microsoft .NET Framework 4 to run.
EDIT: Updated version with unself tool included. Version information also added. Various buxfixes including 64-bit OS support. More error handling added + get Content ID automatically.
I am updating the tool to work with scetools instead which should be able to handle NPDRM files. Please test to see if it works with 3.40/3.55/4.21/4.30 and report back.
Remember that you can find this application and many more here:
Homebrew Application List/PC Homebrew Creation Tools Updated For 2012