iTunes Sync is a freeware to export Playlists to other mp3 players and usb keys
Follow these steps to copy songs (i.e. playlist) from iTunes to an MP3 player or USB key, or USB attached drive.
First start the iTunes Sync programme then start iTunes:
Step 1: create a playlist in iTunes
create a playlist in iTunes and include all songs that you want to copy to your USB key
Step 2: configure your USB key in iTunes Sync
right-click the iTunes Sync system tray icon and click “Configure Devices”
select a subfolder on your USB key that you would like to synchronize to
select the playlist in iTunes that you want to copy to your USB key
Step 3: synchronise your USB key with the iTunes playlist
right-click the iTunes Sync system tray icon and click “Synchronize Device”
once your MP3 player (USB key) and Drive is selected, click the “Sync MP3 Player” button
once the Synchronization is complete just click the Ok button on the notification and close the “Synchronize Device” window
note: this post is translated in Dutch