Trying to identify component for cloud composite application

In this post I try to figure out if I can find cloud component (free at the begining for low use, pay-per-use) usefull to build a composite application (like a mashup).
To start I define "first order" lists of required/optional components, then I try to fill it...

I publish this post in a draft state, because i'd like (dream) have comments and or cloud conponent suggestions.

Main conponents for an application

• Identification/authentication
• Navigation view (if graphical. Not if there is a graphical client side)
• Communication
• Functionnal Services
• Stograge

Optional component

• mail sender
• document server
• money registered suscriber

Provided components

• Identification/authentication 
• OpenId
• Google account/apps : 
  plateform as a service but contains an authentification API allowing google account usage (good or bad idea?)
  
  (see http://www.google.com/apps/intl/fr/business/index.html#utm_campaign=fr&utm_source=fr-ha-emea-fr-bk&utm_medium=ha&utm_term=%2Bgoogle%20%2Bcloud)
• Navigation view (if graphical. Not if there is a graphical client side)
• mainly language provided (google apps for example)
• BeaconPush : 
  Beaconpush is a push service for creating real-time web apps using HTML5 WebSockets and Comet.
• Functionnal Services
• Mainly language provided (google apps for example...)
• Communication
• http://effectivemessaging.blogspot.com/2009/02/messaging-in-cloud.html
• Amazone SQS
• http://cloudfoundry.com/ ; rabbit mq...
  http://blog.cloudfoundry.com/post/8713844574/rabbitmq-cloud-foundry-cloud-messaging-that-just-works
• Stograge
• amazone, google apps

• mail sender 
• Sendgrid : SendGrid replaces your email infrastructure so you don't have to build, scale, and maintain these systems in-house. 
  
• document server
• money registered suscriber
•  Spreedly :help for register subscribers and deals with "making money"

Draft part...

References :

• Cloud Services (from http://www.slideshare.net/gr8conf/gr8conf-2011-mybalsamiq)

• Amazone ws :

compute, storage, payment, billing, web trafic

• Cloud computing