Last March I wrote a preview post showing off Lala's upcoming iPhone app, which gives users the ability to stream their entire music collection from the cloud, without having to worry about syncing their files. At the time Lala wasn't ready to give a release date for the app, but our impression was that it was due out fairly soon. Obviously that wasn't the case. But now we've gotten our hands on the latest version of Lala for the iPhone, which was just submitted to Apple for approval. And it's safe to say that it was worth the wait.For those that haven't used Lala before, here's a quick overview of the service: Lala revolves around the concept of the 'web song' — you're allowed to listen to any song you want totally free exactly once. If you like it, you can then pay 10 cents for the right to stream it as many times as you'd like from then on. This means that you can 'purchase' and entire album for around a dollar. You can also use Lala's Music Mover tool to upload your entire library of MP3s to the cloud free of charge. This is all built on top of a very slick interface, but so far it has come with one downside: because all of the songs are streamed, users didn't have a way to access them when they weren't at a computer. Lala's iPhone app changes that.