Need a fast and easy way to organize your files? PlayStation Portable homebrew developer Mediumgauge has released an upgraded version of PSP Filer, bumping it up to version 3.9.

The dev made a number of changes in this version, including some bug fixes and a couple of new features. Anyway, here's the changelog from the Mediumgauge's website:

general:
fixed a bug Filer was crashed when it opened a broken mp3 file.
added a feature when ripping UMD image to append extra records that could not be accessed from filesystem. (bottom 2k-6kbytes)
filer:
added a feature to view Kbytes / Mbytes mode.
added a feature to set timestamp of file/folder to NOW.
fixed a bug in Russian mode Filer was crashed when it opened file information.
added to show "filesystem size" and "described size in ISO" in UMD device information.
text viewer:
fixed a bug Some characters could not be drawn in EUC-jp mode.

Check out the readme file that comes with the download before anything else. The readme details controls, use, and some tips so it's a must read (also, it's in seven different languages, so no excuses).