PHP images server

Hi List,

My website uses a lot of external images coming from many different
websites. Those images are sometimes small, sometimes big, and to
reduce the loading time of my pages and for better uniformity, I've
built a small PHP images server that resizes to a predefined set of
dimensions the images if necessary. To save on CPU usage, the resized
version is stored on Amazon AWS.

When requesting an image of a specific size, if the resized image
exists on AWS, that image is used. The images server then redirects
the browser to the AWS URL.

I don't believe having 80 redirections is a very clean solution so, my
question is: How can I optimize my process while keeping the load on
Amazon's servers?

Thanks in advance,

-- 
Jean-Michel