By the way, the Rails Tutorial site itself is also hosted on Heroku. By setting the appropriate header, I've arranged for Heroku to cache the site's static page

By the way, the Rails Tutorial site itself is also hosted on Heroku. By setting the appropriate header, I've arranged for Heroku to cache the site's static pages, which on subsequent requests get served with blazing speed (see, e.g., http://docs.heroku.com/http-caching http://docs.heroku.com/http-caching). (Because of its read-only file system, Heroku doesn't support Rails page caching, but that's OK: their Varnish cache (http://varnish-cache.org/ http://varnish-cache.org/) is even faster. :-) Thus, though designed principally for dynamic applications, Heroku is also great for static content.