Playlist Folders

[theriseoffred]

This seems like a really obvious idea to me, so it surprises me that I haven't found this as part of Winamp, available as a plugin or even on the wishlist.
Before I started using Winamp I used to group my playlists into folders in the ML window (left sidebar) of *POS media player* to organise them. Surely it can't be too hard to incorporate a similar feature - with folders or tags or something - especially since there is some sort of playlist folder feature when syncing my iPod (with ml_ipod)?