CL-S3 is a Common Lisp library that implements a client interface to the Amazon S3 Web Service.

More specifically, CL-S3

You can download the code using the URL or from S3 itself using the URL

CL-S3 was written by Sven Van Caekenberghe and is available under an LLGPL license. The current release, dated May 30 2007, is available as a tarball only.

Please read the full Amazon S3 documentation and study the Common Lisp source code before contacting me with ;-)

There is an interesting post on Nicky Peeters' Blog showing how to get started using CL-S3.