I'm not sure this improves the situation much. In fact, it probably will only make things worse since you've got an additional point of failure.<p>The proxy will keep your site up if S3 goes down, but if the proxy goes down you're done. This strategy hinges on the assumption that your caching proxy is going to be more fault tolerant than S3. The recent problems Amazon has been having aside, that's not a gamble I'd be willing to make.<p>Nevermind the fact that even under the best circumstances this is only useful for reads.