The AmazonS3 module allows the local file system to be replaced with S3. Uploads are saved into the drupal file table using D7's file/stream wrapper system.
The Materialized Views system originally written by David Strauss for Drupal.org and being extended for Drupal 7 and Views as a Google Summer of Code project.
Attention: this module is experimental. Not recommended for live sites. Testing and feature requests are welcome to get a stable module.
This module is based on the Facebook's BigPipe functionality to serve pieces of pages instead of complete pages.
It requires the Jquery Update module to use the jQuery.live function and BigPipe most of the links but the ones that already have other functionality. You can integrate it with Drupal Chat and get the desired non-blinking effect.
What it does is to load a javascript "manifest" into a hidden iframe with the proper instructions of what is needed to do to update the current page and perform the necessary changes. Basically, it loads contents, scripts and styles dinamically.
Currently, most of the performance gain is on the client side. On the server, processing is almost the same as without BigPipe. This is intended to be improved by integrating with the Context module and find an intelligent way to or not to process certain stuff.