Playlist Manager will allow you to create, edit and delete playlists and play them. Playlist Manager will save your file as .m3u directly under your chosen music folder which can then be played by PSP music player. Playlist Manager has its own music player that will allow you to play your selected music file, folder or playlist.

There are no restrictions on file addition or removal – you can keep on adding the same file and in any order. Playlist Manager can recognize and play playlists and music files from sub folders. You can use Playlist Manager as any other MP3 Player!

http://forums.qj.net/f-psp-development-forum-11/t-releaseplaylist-manager-v20-114376.html