What's needed to develop a database in the cloud?

Question

What is needed (in general terms) to create a service like MongoHQ or SimpleDB?

Thank you

Answer 1

Cloud Computing – A Primer
http://www.ipjforum.org/?p=199

See Also:

Is the Relational Database Doomed?
http://www.readwriteweb.com/enterprise/2009/02/is-the-relational-database-doomed.php