If you’re hosting a blog on a shared server and you’re concerned about page loading time, would it at least theoretically be better to host the images in an Amazon S3 bucket and then just link to them?
As Google apparently takes page loading into consideration, will this possibly improve search rankings?
I am not sure about search rankings but it really improves your page load speed. It commonly known as CDN. You can use this http://wordpress.org/extend/plugins/w3-total-cache/ and it has an option to select a cdn that includes the amazon server. So managing images between your wordpress and the amazon server is pretty easy by using this plugin. Thanks