After a swirl of rumors that Apple was in talks to acquire music-streaming service Lala, the Wall Street Journal reported yesterday that the companies had reached a deal. Exact terms were not disclosed.

Lala, a four-year-old private company, offers a terrific Web-based music streaming and download service that lets you listen to any song for the first time for free, and as many times after that for $.10 per song. Unlike with iTunes purchases, you never own the file. Instead, you buy the right to stream it from any browser at any time, even from mobile devices.

But here's where it gets really good: Songs you already own through your iTunes purchases also become yours to hear through Lala AT NO EXTRA COST. So in a way, Lala can be used as a kind of iTunes backup. Sign up for free and transfer your iTunes libraries and play lists right over. I know several people (including me) who would have benefited from such a backup after their hard drive crashed. If you've paid the $.10 for streaming and you decide to buy the song outright, you pay just $.79 more to download an MP3, which isn't encumbered by DRM yet still compatible with iTunes (and Windows Media Player).

There's been lots of speculation about what Apple is up to. After signing up today and sampling Lala, I think the most logical move would be, as Technologizer's Harry McCracken put it: to "merge all of Lala's goodness into iTunes itself, creating a seamless experience across Mac, PC, iPhone, and iPod." Put more simply, it would make your music available anywhere from any device.