It works, but not well enough to continue to using it. iTunes just doesn't handle remote access for the library well. When you have JungleDrive going, where you can actually see all the files that are constantly getting updated and rewritten, it becomes clear that anything other than local drive (or at least LAN) access is an issue.

I tried two different methods. First, I actually uploaded my entire catalog and the XML/indexes to S3, then simply made the local iTunes folder a symbolic link. This way both the library files and indexes are on the S3. The theory being that as I listen to files at work, and maybe add a new song file, then when I get home and fire up iTunes, it's identical. In a perfect world, this is the best solution. All computers treat the iTunes database as their own and it doesn't matter where changes are made.

Unfortunately, any change (including simply the fact iTunes increment the Times Played counter on every song as you listen) requires reuploading those index files. At work with huge pipes, not a huge deal. On the DSL or Wifi, major problem. After every song plays, it's uploading 50Meg worth of indexes.

With that option not working, I then undid the symbolic link, put the indexes back in a regular local iTunes folder, and simply set the actual library of songs to still use the Amazon drive.

In this mode, at least it's not updating after every song, but the benefit of having multiple computers with identical libraries immediately goes away. Any new song has to be added separately to each computer. The biggest problem is that some features, like Genius, suddenly decide to reindex which requires scanning your library (and sending info to Apple). With the songs in the cloud, iTunes basically causes Jungledisk to download each song to "scan", so suddenly my 50GB of songs are being re-downloaded one at a time so Genius can do a scan (no clue why it can't simply send the titles, I don't really know what it was doing that it wanted full file access.. but it does, so Jungledisk was busy downloading until I aborted that process Forcefully.)

Any updates to any song still require that download/upload, such as changing a tag. I changed the tags on three podcasts to be "Podcasts" instead of whatever they were before, which meant iTunes (JungleDisk) downloaded each file, rewrote the tag, and reuploaded those files. Even at work it took several minutes.

With my MacBook Air in particular, streaming music off S3 is very hit or miss. Many places I tried didn't have the best download. Even at the massive public library downtown, they throttle traffic during busy periods (like when there's literally 1000 people in there on their laptops and in-house computers), so my download speed was 128kpbs at peak times. Not a huge deal for web pages, but music no longer worked. (Streaming radio works because they're compressing heavily, but with iTunes downloading 3Meg files per song, performance was not good.)

So ... while everything mentioned here works in theory, real world performance just isn't up to the task. I'll keep my S3 drive because having unlimited backup space is great (especially since it just costs .10 cents per Gig/per Month to have it just sit there), but constant usage just isn't ready for prime time.

As a side note, this does prove that the DSL/Cable style of Broadband, i.e. fast download/slow upload because we're "consumers of data" really breaks down under the Cloud Computing or Storage model where we need full duplex access at high speeds. I have no doubt in my mind that cloud storage at least is the next major thing, but the infrastructure has to be there first.

Sugarsync (www.sugarsync.com) seems like a promising, but incomplete solution. They don't charge for bandwidth, and they support streaming non-DRM MP3's and AAC. But you can only backup from your local drive. You can stream from the cloud using their mobile app, but that's it. Your playlists, Apple TV, and iPod experience are shot.

Drives that have more capacity need to be more energy-efficient. Networks need to be faster. The real solution, IMO, is that compression envelope for the files needs to be pushed.

You seems to be an advanced music listener. Let me tell you about Zicmama. As Jungledisk, It is a network drive. But it gets your mp3 copied from other music library ;)

Try it and open an account an http://www.zicmama.com Then connect your Webdav ZicDisk... Be gentle, this is still a beta french ;) Any interested translator?