S3 Uploader Rails Example (user contribution).
Is able to use XHR uploads directly to S3, despite S3 not supporting Access-Control-Allow-Origin, by hosting an (iframed) upload form on S3 itself (tricksy!)
Using the plugin to Upload directly to S3 (user contribution).
Uses the iframe-transport fallback, so lacks niceties like the progress bar
A fully IHttpHandler based PHP server-side clone abstract class for uploading files. Class main propose is to upload files (supports high-quality images uploading) (Contributed by Yahav Gindi Bar).
Backload. A professional full featured server side file upload controller/handler for ASP.NET MVC4 (ASP.NET Web API and Standard ASP.NET WebForms supported). It has a very rich set of configuration options but also a zero configuration feature. It supports complex storage structures (set client and server side), image resizing, cropping and conversions, content type based subfolders, tracing, events, etc. Backload demos and examples