The EC2 Image Locator allows you to find and clean-up Amazon EC2 machine images (AMIs) stored in your S3 buckets. Normally, you create an AMI by bundling up an EC2 instance, storing the content in S3, and then registering the AMI with EC2.
Analyze Bucket - For a number of reasons, it's easy to lose track of all the AMIs stored in S3, or to find AMI files that are no longer registered with EC2, etc. The EC2 Image Locator consists of a background worker that examines one S3 bucket at a time and locates all of the stored AMI files.
Deregister - If you created and registered an AMI, but no longer want anyone to be able to use it, you can tell Amazon to deregister the AMI so that nobody will be able to launch a new server with the AMI. NOTE: Deregistering an AMI does not delete it. The AMI will continue to exist in your own S3 bucket until it's deleted.
Delete - If you delete an AMI, you will permanently remove it from the S3 bucket. It's important to deregister an AMI before you delete it, otherwise users will still be able to still see and use your AMI. So, users will not be able to successfully launch an instance because the image will no longer be in the S3 bucket.
A simple S3 browser displays the number of AMIs in a bucket.