Tooled up with plenty of Greasemonkey and a server-side script, I had a go at the 'Enter the correct artist for the album' game at Amazon's Mechanical Turk and managed to do about 150-200 ($3-$4 worth) in an hour. I don't think anyone could do it much faster, unless they were just guessing (though I did occasionally get sidetracked opening tabs to download a few of the albums from eMusic), but that's still a reasonable amount to earn if you live somewhere not too expensive.