New free service from Amazon called AWS Identity and Access Management (IAM) allows you to create Users and manage the permissions for each of these Users within your AWS Account.
A User is an identity (within your AWS Account) with unique security credentials that can be used to access AWS Services. IAM eliminates the need to share passwords or access keys, and makes it easy to enable or disable a User's access as appropriate.
IAM offers you greater flexibility, control and security when using AWS.
S3 Browser does support IAM, providing you an easy to use interface to manage your Users, groups, and permissions.
To Open IAM Manager click Tools -> Access Manager (IAM)

Click Tools -> Access Manager (IAM)
Access Manager (IAM) - Main Window

Click Tools -> Access Manager (IAM)
To Create New IAM User
Click the New User button

Click the New User button to add new IAM User
Add New IAM User dialog will appear

New IAM User dialog
- Type a name of the user to create
- Type a path for the new user (this field is optionial)
- Click Create new User
S3 Browser will create new IAM User and new Access Key ID and Secret Access Key pair.
This page will appear after user created.

New IAM User has been successfully created. Save Access Key ID and Secret Access Key.
Save Access Key ID and Secret Access Key! For security reasons there is no way to restore them later.
Click Copy Keys to copy Access Key ID and Secret Access Key to clipboard.
Click Create another user if you want to create more users and Cancel otherwise.
To Edit Existing IAM User
Select the user you want to edit and click Edit User

Click the Edit User button to edit existing IAM User
Edit IAM User dialog will appear

Edit IAM User Dialog
- Type a new name for the user
- Type a new path for the user (this field is optionial)
- Click Save Changes
To Delete IAM User(s)
Select user(s) you want to delete and click Delete User(s)

Click the Delete User(s) button to delete IAM User(s)
Confirm user(s) deletion

Confirm IAM User(s) deletion
To Add New IAM Policy
Select the user and click the New Policy button

Click the New Policy button to add new IAM Policy for selected user
Add New Policy dialog will appear

New IAM Policy Dialog allows you to specify iam policy name and policy document
- Type a name of the new IAM Policy
- Specify IAM Policy document
- Click the Add new policy button
S3 Browser will add new IAM Policy for the selected user.
To Edit Existing IAM Policy
Select the user and policy you want to edit and click Edit Policy

Click the Edit Policy button to edit existing IAM Policy
Edit IAM Policy dialog will appear

Edit IAM Policy Dialog
Make changes in the Policy Document and Click Save Changes
To Delete IAM Policy
Select the user and policy (or policies) you want to delete and click Delete Policy

Click the Delete Policy button to delete IAM Policy or Policies.
Confirm deletion

Confirm IAM Policy deletion