We have a new project called Amazon-S3 Explorer which can explore your Amazon S3 account.  We also have an S3 plugin that can be used in any application. It interfaces with S3 via REST and it can handle pretty much any operation on Amazon.  Below you can see some screenshots of our S3 explorer.  You can get the source from our codedepot SVN, you can download the latest release from here, or you can download our entire project pack from forgebox.

We are still restructuring our code depot respository layout, but soon you will find our major extensions to be laid out in our codedepot folder, with projects in incubation and the sorts.  Thanks to our plugin architecture, we can really extend the core with extra functionality with much ease.