There are plenty of cloud storage services to choose from, but there are few that are particularly good. Amazon hopes to become part of the latter group with the introduction of Amazon Cloud Drive, a consumer-oriented service that allows users to back up their local music libraries and play them remotely from anywhere via the Web or Android device.

According to Amazon, all US-based Amazon customers automatically get 5GB of Cloud Drive space where they can upload their music libraries. The files must be unencrypted AACs or MP3s, and they can be uploaded at their original bit rate. Those who purchase an album from Amazon's MP3 service get the sweetest deal, though—20GB of space—and all new MP3 purchases will be automatically copied to your Cloud Drive without counting against your storage quota (you can still download the MP3s, too).

Essentially, Amazon is offering customers between 5 and 20GB of free space to do with as you please, and unlimited space for you to stream the MP3s purchased from Amazon. (Those who want to purchase more space can do so for $20 per year for 20GB, too.) Amazon officially supports Web streaming via IE, Firefox, Safari for Mac, and Chrome, but users of unsupported browsers (like Mobile Safari on iPhone) have reported good luck with it so far. Android users can also download a specialized Cloud Player app, which is apparently just an addition to the already existing Amazon MP3 app.

“Our customers have told us they don’t want to download music to their work computers or phones because they find it hard to move music around to different devices,” Amazon VP of movies and music Bill Carr said in a statement. “Now, whether at work, home, or on the go, customers can buy music from Amazon MP3, store it in the cloud and play it anywhere.”

Amazon is leveraging its popular Simple Storage Service (also known as S3) in order to offer Cloud Drive to "regular" users who may not have the tech background to make use of S3. And, although the main focus here is music, users can store all manner of other files without any problem. In fact, Amazon may only be using the music thing as a way to slip into the online storage business—it's possible that Amazon has even more ambitious plans for Cloud Drive, like offering desktop integration and becoming a serious Dropbox competitor. (Or that may just be our secret fantasy. Make it work, Amazon!)

Still, even if the focus remains on music, Amazon has managed to beat some other big names to the punch by offering a digital locker service that allows you to both stream and download songs from wherever you are. Apple is rumored to be working on its own cloud-based music service for MobileMe with largely the same features: music downloads plus online music storage for streaming to an iOS device or computer. That's not expected to come until this summer or later, though. It's impressive that Amazon was able to strike a deal with the record labels before both Apple and Google. (Update: It turns out Amazon hasn't struck a licensing deal yet with all of the record companies, according to the Wall Street Journal.)

Our early experiences with Amazon Cloud Drive under Mac OS X were positive. Even when only using the Web interface, it was easy to upload multiple files at once, and if you upload music with decent tags, Amazon will also split out the Album and Artist for easy sorting and organization. Although Amazon can't import your playlists from software like iTunes or Windows Media Player, it lets you create playlists anew, so you're not limited to cherry-picking through your library for every song. If you choose to download your songs back to your local drive, though, you need the Amazon MP3 Downloader (the same application that is required when you buy Amazon MP3 music). Overall, we like the service and think it has great potential. And who can argue with free remote storage?