"Very helpful, but S3 is not a CDN - Amazon's CDN is CloudFront (which can easily be extended from S3, however.) Also CloudFront is quite slow as CDNs go but it is easy to set up and administer. You might also consider resellers that offer faster networks, such as GoGrid (resell EdgeCast) or LiquidWeb (resell L3). [Disclosure: while I am a photographer, I also work for a CDN.]" - Anthony Citrano