Saving WordPress Media to Amazon S3 (Teaser)

I like Linode, but hey, disk is expensive (\$1/GB/month), especially compared to things like Amason S3. So why can't I store my WordPress media in S3 without relying on local disk at all?

I've been thinking about this for a long time, but only now do I have a hacked version of WordPress, a small plugin to modify upload file paths, and a mutilated copy of the Zend S3 client which patches in some necessary functionality. Uploads go directly into S3 without so much as touching wp-content. (OK, the file does touch the local temp directory while uploading, but it doesn't stick around.)

Now, to make it usable.