Database
- Redis
- Casandra
- MySQL (RDS, while nice, isn't quite agile enough) (other besides RDS)
- PostgreSQL
Queueing
- RabbitMQ
- Beanstalkd
- Gearman
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- Thinking Sphinx
Database
Queueing
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The categories of products you are asking about are available in the cloud (DBMS,NOSQL, Queuing). Perhaps not the same implementation though.
Microsoft and Amazon both have queuing and noSQL database solutions in the cloud.
Microsoft has SQL Azure as well, which is a cloud version of SQL Server. This is equivalent to MySql/PostgreSQL in your list.