Using Amazon S3 to fix URL shorteners 

Joe Moreno is a smart and creative mofo.

He's got the kind of smarts that figures out how to simplify what appears to be a vexing and insoluble problem, to the point where it's no longer a problem. That's the best kind of smarts there is, imho.

Anyhoo... Joe figured out how to use a little-used feature of S3 to make URL-shortening both trackable and future-safe. Pretty good!

I can let you put stuff in my bucket 

The key feature is that I can let you put stuff in my bucket without giving you my access keys. You use your own credentials. Mine stay private. This means I can use S3 to store sensitive information without trusting you not to misuse it, because you have no more access to it than you did before.