I want to organise a bunch of files into a collection and then is one easy move transfer that to my ipod / mp3 players.

Naively I though a playlist would do this but apparently it doesn't work (at least for me there appears to be no way to do this amarok 2.4.0).

I've hundreds of albums and copying them one by one is very tedious...

I may well have done something wrong but I'm stuck, any clues?

there is an Amarok script called "Copy Selected Tracks" http://opendesktop.org/content/show.php?content=119179 it can be dl'ed and installed from within Amarok using the script manager. The description appears relevant for your needs

ps - 2.4.0 is bit old, you should up to 2.4.3