Standalone Rockbox Cover Generator
Source (required if based on other people's work):
A python script to export cover images from the Amarok database to the cover.bmp format required by Rockbox. Unlike other scripts I've found, this one is able to export every cover known to Amarok in one shot, rather than relying on you to play one track from every album via the Amarok UI.
Inspired by similar scripts by asiemieniak and Chain.