Subbu Allamaraju shows that a significantly more RESTful api than Amazon's SimpleDB is not so difficult to conceive.
The SimpleDB API is neither resource oriented nor HTTP friendly. Having said that, how should such an API be designed in a resource-oriented manner? Here is my take, a version-0.1 of a RESTful SimpleDB. In the design below, I tried to keep the semantics of this version as close as possible to the official SimpleDB API