We host our Magento store internally with a not so amazing Internet connection. It’s good enough to process the shop, but images take a while to upload to the visitor.
So what we have done is tweak the image.php file in app/code/core/Mage/Catalog/Model to point the images to a public space on RackSpace.
It’s not an ideal method though with the admin console complaining that images don’t exist and other random mess ups.
So I was wondering if anyone has implemented such a solution which I can use for our shop?
I imagine it will need to ignore the cache check as it cant upload to rackspace.
You can use the option of the backend of Magento

And redirect the trafic of images to another server(CDN).
There is one more solution, for example the module of one pica CDN with the option to select many CDN( amazon, custom cdn, etc)
http://www.magentocommerce.com/magento-connect/onepica-imagecdn.html