|Pandora One Gift Card|
Pandora is one of the best streaming music services, offering both a an ad-supported "free" service and a paid ad-free service (a so-called "freemium" business model). A principal Pandora differentiation (as compared to competing services like Google Music All Access, iTunes Radio, Rhapsody, and Spotify) is Music Genome Project technology, which does a good job of selecting music that is similar to music you already know and like.
In the beginning the free Pandora service was attractive given ads that were relatively few and unobtrusive, but over time ads have become both more frequent and more obtrusive, to the point where they are now downright annoying, which of course pushes subscribers toward the paid service.
That wasn't so bad when the paid service was $36/year or $4/month, but Pandora ended the annual subscription option and raised the price of new subscriptions to $5/month (⅔ more expensive than the original annual subscription on a monthly basis).
Fortunately, there is still a way (as of this writing) to get the original $36/year subscription price: Pandora One Gift Card at Target.com (not in Target stores). Where you receive your gift card(s) in the mail, you can add them to your Pandora account by activating them here.
This probably won't last forever, so you might want to stock up with more than one card.
Update (4/2016): Pandora One Gift Card at Target.com is no longer available.