Glancing over the Octopress plug-ins list yesterday I noticed something I hadn’t seen before, an Image tag & uploader for S3. Curious to tinker around with it I set-up an account for S3 and integrated it today to decrease my blog header background image size and serve it from the cloud with caching.
Update 2016-11-22: You can find the open source Octopress version of this blog circa 2015 right here. Once you're ready to move on from GitHub try Simple Websites with Jekyll and Docker. And, once you've nailed that approach, try going for PageSpeed 100 with S3 and CloudFront.
Follow along to learn how to host images on S3 with Octopress.