I interrupt my regular content flow for this commercial tip.
Every so often, Best Buy runs a sale on iTunes gift cards. Right now, they're selling all their iTunes gift cards for 15% off. No strings attached, no sales tax, nothing. I'm not sure how Best Buy can do this, if they buy the cards at a discount, or if they're using this as a loss leader (which doesn't seem smart in an age when online shoppers can just spearfish loss leaders without ever setting foot in a store) or if they receive any subsidy from Apple for this promotion (also seems unlikely).
Whatever the reason, it's a good deal for consumers like me who buy lots of apps for my iPhone and iPad or who occasionally rent movies through iTunes to watch on my iPad or AppleTV. Make sure to purchase the iTunes gift cards, not the App Store gift cards, as I think the iTunes gift cards can be spent on a wider range of products, not just all media but apps and books from the iBookstore (I'm not certain about that, but it's implied by the fine print).
15% off is nothing to sneeze at in these tough economic times. Best Buy doesn't run these sales often, but every time they do, I load up my iTunes balance.