With iTunes you can get a random list of songs synced on to your iPod until your device is full. I want to do this with Foobar2000 but have a random list of albums added until full.
There is no direct way to do it, but, provided your albums are stored as a collection of files within a single folder, you can do the following:
Create a playlist with the music you wish to choose from. Select all songs (Ctrl-A) Right click -> sort -> randomize Right click -> File operations -> Copy to -> ... Choose a folder to copy to (Ideally your player), tick "Copy entire source folder content" and start copying. Choose "Skip" if prompted to deal with a file conflict. If copying to player, you'll get an error when it's filled to capacity, otherwise stop when enough files are copied.