1 Regarding the [[Amazon_S3_Plugin|plugins/amazon_s3]]:
3 Amazon S3 doesn't seem to support automatic GZIP encoding content (such as HTML, JavaScript, and CSS) that might be compressed by a full-capability webserver. (I'll also note that NearlyFreeSpeech.NET doesn't support compressing out-going files on-the-fly). However, Amazon S3 does support setting some response headers, such as Transfer-Encoding and the like.
5 One possibility of decreasing bandwidth costs/download sizes would be to GZIP all content on the site and set the necessary header... however there are certain browser compatibility issues to be navigated.
7 Another side item that would be useful potentially would be to have a config option to create a mapping of files that can be gzipped as an alternate name...
15 Would take all js files and gzip them w/ the altered extension. *This* could allow for using JavaScript to customize what other JS/CSS code gets loaded in based on browser-detection JS code.