Amarok: Again the album art issue

Amarok doesn't handle album art well for me. They can't help some of the main issues: Amazon's API restrictions have forced the developers to switch to last.fm for automatic cover fetching, which apparently is not implemented in v2.2.0 yet. Additionally, for classically minded listeners like me it's generally difficult to get the matching cover without manual intervention (sorting out composers, artists, correct album title).
It doesn't get easier if you want to synchronise an iPod or similar and need to merge collections from different sources.

OK, I'll stop whinging.
Amarok can't display id3tag-embedded cover art yet (see this bug), but it does display images saved to the album directory, provided they are named album.jpg. Note that you have to do a complete collection re-scan to display new or changed images.
If the album art is already organised over the Amarok database (saved to ~/kde4/share/apps/amarok/albumcovers/large), the export-amarok-covers python script can batch export the images to the album folders (Amarok 1.x only). For 2.x, there's the copycover script on kde-apps.org, which exports during playback. The exported file is usually cover.png, so here is a shell script (tolerating white space file names) for batch conversion to album.jpg:

find /your/mp3/directory -type f -name "cover.png" | while read FILE
 do
  newfile=`dirname "$FILE"`
  echo $newfile
  cd "$newfile"
  convert cover.png album.jpg
  # rm cover.png #uncomment to delete cover.png
 done

GTKpod will transfer the album art from the folder to an iPod by setting the file name to album.jpg in Edit->Preferences->Metadata->Add cover art using the file name template
It should be theoretically possible to update the artwork from amarok directly. Check out the Ultimate IPod Guide.