I don't know exactly which forum this belongs in, but Best Buy has an online sale for the gift cards - buy 3 $25 gift cards and get the fourth free ($100 worth of iTunes for $75):
http://www.bestbuy.com/site/olspage.jsp?type=category&id=pcmcat137500050042
http://www.bestbuy.com/site/olspage.jsp?type=category&id=pcmcat137500050042