From the Amazon SimpleDB documentation:
Amazon SimpleDB REST calls are made using HTTP GET requests. The Action query parameter provides the method called and the URI specifies the target of the call. Additional call parameters are specified as HTTP query parameters. The response is an XML document that conforms to a schema.
Note
If the length of the query string that you are constructing exceeds the maximum length of the HTTP GET URL, use HTTP POST and submit the query string parameters in the body of the message.
Excuse me??? This must be the single most egregious abuse of the “REST” term I ever saw. Listen, Amazon, just because you use HTTP and XML and do not use SOAP, you cannot just call it REST because you think it’s sexy and pretend that you’re not looking stupid.

