This plugin (widget ready) allows you to retrive latest feeds from Google Buzz service. It has some advanced options like caching
Easy Object Cache provides APC user caching functionality if not available on your server, and lets you control the drop-in plugin object-cache.php.
Fragment caching for WordPress themes and plugins
Hash (affiliate) URLs and turn them into pages for your blog or simply cache URLs.
Activate your site with client-side caching to maintain access to users even when your server is unavailable.
Fastest cache system for WordPress Blogs to improve performance and save the World.
Kalimantan is a plugin that integrates Gallery 2 with your WordPress 1.5.
Staticize Reloaded is a plugin to make your site faster by caching the output of some WordPress pages. It creates a unique key based on the page varia
Shave off a few milliseconds on your site loading time
Adds the ETag, Last-Modified, and if appropriate 304 headers to HTTP responses generated by WordPress for more efficient caching.
Thesis Cache(r) is designed to integrate WordPress object caching with your thesis theme by giving you page-by-page cache control.
Caches multiple users automatically on post and comment pages to radically reduce mysql queries for plugins that get_userdata.
Adds ajax search, live search, relevance based search, query logging, query caching, search analytics and tons of other cool features.
Substantially increase performance of localized WordPress by caching the translation (l10n) object. Supports multiple languages.