We know that Google's been thinking about launching a music service, and now the crazy kids at Billboard are reporting details of a proposal that the search giant's been circulating among the major labels. Apparently the company is pursuing a sort of hybrid digital download store / cloud-based locker service, with the store offering individual tracks or albums, while the "locker" would scan the user's hard drive for music files and, upon finding tracks that Google is licensed to offer, allow the user access to them on the cloud (presumably you won't be actually uploading your MP3s to the service, just streaming their content once it's determined you have a copy of your own). And since you can't offer any service without a little "social networking" on the side these days, Google would like to give users the opportunity to send each other tracks, which they could listen to once -- and then either purchase or preview (um, review) in thirty second snippets, similar to Lala. There's no word yet on which -- if any -- labels are willing to take the bait, but we'll let you know as soon as we hear anything else. Promise.