Amazon beat both Google and Apple to the punch this week with the launch of Amazon Cloud Drive and Cloud Player — an online storage system for music, movies, photos, and documents. Cloud Player lets users stream and download music stored in the newly launched Amazon Cloud Drive to virtually any Web-connected device—with the noted exceptions of iPads and iPhones. Rumor has it that Apple is working on a similar Web-based iTunes (Free, 4 stars) service, and Google’s purportedly getting into the game with Google Music.

Starting  with 5GB of free storage, you can upgrade for $1 per GB ($20 for 20GB a year), but Amazon is offering a pretty great deal for the remainder of the year — buy an MP3 album on and get upgraded to 20GB of storage for a year. Additionally, if you buy any music from Amazon, you can have it automatically saved to the Cloud Drive for free.  More than just a web interface, Cloud Player also works in conjunction with a free Android app, so you can stream your music from any Android device.

Using Amazon Cloud Drive is a breeze for current Amazon customers.  After signing into your Amazon account, you can launch the Cloud Drive interface, where you’ll be able to search and store music from your computer and iTunes, as well as any other files you want to store. Uploading is simple and straightforward: just select the files you want and upload. It’s that easy. Plus, you can organize in playlists so you can listen to your favorite songs without any stops or pauses.

After you’ve uploaded all your files you can play them via the Cloud Player, which launches right in the same screen.  Cloud Player has a few limitations. You can’t upload audiobooks, ringtones, files larger than 100MB in size, or tracks recorded in FLAC, OGG, WAV, or any other types other than AAC and MP3. If you prefer to listen to lossless music, this service is of no use to you. You can, however, store those incompatible files in Amazon Cloud Drive, but they won’t appear in the Amazon Cloud Player, as Cloud Player only displays playable tracks. You can also upload video clips (AVI, MOV, WMV) to Amazon Cloud Drive, but they also don’t appear within Amazon Cloud Player.

Add in the Android App, which you can download for free and get access to all of your stored music and playlists, and Amazon has pretty much left its competitors in the dust. This is especially great for music addicts who have huge libraries, since they can get all of their tunes at their fingertips without using any of their smartphones’ on-board storage.

Amazon’s Kindle has proven to the industry eReader leader, now Amazon has taken a giant leap into online media storage and listening.