Useful tip for sharing an AMI between two accounts.
1. Capture your AMI in the normal way.
2. Once the AMI has been captured, click on the "Permissions" tab.
3. From there, under "AWS Account Number" click on edit and enter the AWS account number of the account with which you would like to share the AMI.
4. Once you've shared the AMi, open up the other accounts.
5. Begin the process for launching a new AMI. From the left hand menu, choose My AMIs and the make sure, under Ownership, you choose, "Shared with me".
6. Search for the shared AMI by name or ID and hey presto, the newly shared AMI can now be used within your other account.