I tried a couple of times to get an account from amazon for testing their web services implementation, but I was unsuccessful - I never received a response to my application. On the other hand, I was able to access google's web services using aolserver/nsjava, and I have created a web services package for openacs that integrates the apache axis web service implementation. The apache axis package provides support for both client and server web service implementations, and you should be able to use it to access the amazon web services, assuming that you are able to obtain an account.