You can find the documentation of the current version at docs.zendframework.com
Zend_Service_Amazon_Ec2: Keypairs - Zend_Service
Keypairs are used to access instances.
Example #1 Creating a new Amazon Keypair
create, creates a new 2048 bit RSA key pair and
returns a unique ID that can be used to reference this key
pair when launching new instances.
create returns an array which contains the keyName,
keyFingerprint and keyMaterial.
Example #2 Deleting an Amazon Keypair
delete, will delete the key pair. This will only
prevent it from being used with new instances. Instances currently
running with the keypair will still allow you to access them.
delete returns boolean TRUE or
Example #3 Describe an Amazon Keypair
describe returns information about key pairs available to you.
If you specify key pairs, information about those key pairs is returned. Otherwise,
information for all registered key pairs is returned.
describe returns an array which contains keyName and keyFingerprint