lala
It's a bit hard to tell many of the new online music services apart, from Pandora to Last.fm to iLike and so on. Lala adds a bit of a twist. It's a streaming music service that lets you play any of its 6 million tracks once for free, and $0.10 to unlock it for unlimited future online playing. The twist is that it will also search your own music library, and if any of your tracks are in its 6 million track library, those will be unlocked for unlimited online streaming as well. So instead of having to keep your home computer on all the time to act as your music server, you can save some electricity bills and just stream your music from lala through a browser.
It's one step closer to the universal music locker online, an idea which has seemingly been batted around for years now. The main problem right now is that 6 million tracks is not that large a selection for anyone with reasonably diverse musical tastes, so it's far from an endgame. But the concept is appealing.