Sound Banks/Directory’s - Portable MP3

Sorry if this is in the wrong section but I am hoping for some advice. I was just wondering if anyone knows of any Mp3 Players which have different Directory’s for music, kind of like an IPod where you can create 'folders' to store different music and playlists etc. I am currently creating a project and I need to play different sound bites but I want to put them in separate files for organisation.
Thank you for any help.