Microsoft's $15 Zune Pass subscription service—a pretty sweet deal already—has just porked up their offer by giving you 10 free songs that you can keep every month. We've talked about Zune Pass in our Zune reviews before, but it's basically access to all of the Zune Marketplace for only the price of a CD a month. Since most of their catalog (90% or so, including all the majors and a few indie labels) is already in MP3 format, you can load these free songs on any kind of device you want, like your iPhone or Android phone or PS3 or Wii. They're also announcing the addition of Universal Music Group and Sony BMG to the MP3 DRM-less format (DRM-less as long as you buy the music), the last bits to complete their "majors" MP3 collection. We think the deal is hotness as long as you're OK with the fact that you're renting, not buying; well, you're now "buying" those ten tracks a month, in essence. [Zune]