I've got a tiny lovely player called Sansa Clip and i just felt in love with it! 
Ohh it almost broke my heart after i found out it doesn't support directory based music browsing, ohhhh...
So i've wiped the dust off my good old vb.net 2008, and then, after few moments i had the cure!

This program is quite simple. It has just one button - for creating playlists for all the mp3/wma/flac/ogg files all over the /music/ folder on your players!

Click it - and each folder in the /music/ directory will get it's own playlist, so it's subdirectories wolud get playlists too.
For example:
That's what i have in my /music/: 

Music
├───House
│   ├───2007-2008
│   ├───2004-2006
│   ├───2006-2007
│   └───Old (200x)
├───Bic Runga
│   ├───Beautiful Collision
│   ├───Bursting Through EP
│   └───Drive
└───The Postal Service
    ├───Give up
    └───Le Chevre

And in single click i get these playlists in the root of my player:

All.m3u
House.m3u
House-2007-2008.m3u
House-2004-2006.m3u
House-2006-2007.m3u
House-Old (200x).m3u
Bic Runga.m3u
Bic Runga-Beautiful Collision.m3u
Bic Runga-Bursting Through EP.m3u
Bic Runga-Drive.m3u
The Postal Service.m3u
The Postal Service-Give up.m3u
The Postal Service-Le Chevre.m3u

 

That's almost if i'd browse the directories or even better!

Well there is a drawback - the player is a bit slow on selecting playlists...

 

Be carefull with the options - they gonna wipe all your playlists off the player...
  

Download here: Sansastic!Playlist.zip