Update #4: PBP Unpacker v0.94 has been released by pdc today, and includes a fix for an SFO data bug and various small changes. Enjoy!
Update #3: PBP Unpacker v0.92 has now been released followed directly by PBP Unpacker v0.93 which includes an SFO GUI fix. For those who don't already know, PBP Unpacker is a fully-featured tool for extracting and creating PBP files, as used by the $ony PSP.
Update #2: PBP Unpacker v0.90 has been released by pdc, and now includes some bug fixes and improvements for both the SFO Editor and full UTF8 support.
Update: PBP Unpacker v0.85 has now been released, with changes including UTF8 support for SFO editing (Asian / European characters) and an improved SFO data entry method.
Today pdc released an update to his PSP PBP utility, bringing it to PBP Unpacker v0.80 now! Changes include the addition of an SFO editor and also a bug fix for reading write-locked files.