<i>Normal S3 pricing applies to each version of an object. You can store any number of versions of the same object, so you may want to implement some expiration and deletion logic if you plan to make use of this feature.</i><p>Hehe. Users of VMS learned pretty quickly the DCL command to set the number of versions to 3 or so. That way, they would only have "note.txt;32", "note.txt;31" and "note.txt;30" around, instead of running out of disk quota with all the versions down to "note.txt;1".<p>One of the filesystems for CDs (UDF ?) supports this.