james 12 December 2011 Re: CDN, I have rsync setup between my image cache directory and an image directory on the CDN. When the script detects an image that has already been cached, it returns the URL to the resource on the CDN instead of the origin server. The challenge was it also had to check timestamp and continue to serve from origin until the file was at least 5 minutes old. I do that on a site that gets about 60 million hits a year and it works fine. I wish there was a better way, though.