varnish + pound * lighthttpd or apache 2.2 worker とか考えた。設定方法とかはないよ！

最新 ( 2.0.1 ) の release note 見てみたら

* ESI include support
* Round-robin and random backend load balancers
* Backend health check
* Serve expired objects, until we have a fresh one
* OpenSolaris support
* Much improved malloc backend, particularly on Linux
* Lots and lots of bug fixes
<http://varnish.projects.linpro.no/>

ジュルリ･･･。