Devide Static and Dynamic Content

[solars]

I'm planning to do some similar setup on a server, Nginx in the front, Apache in the backend.
Here is an example if anyone is interested, its german, but the main part is the config anyways: http://www.nginx.de/NginxToApache

My reason for doing this is because I think about isp-control as a nice hosting control for some of my older users and their php site.

The main reason though is that I mainly want to host Rails applications, and nginx is the best choice for this in my opinion.

I'm not sure how to setup the whole server, so any suggestions/discussion if someone did something similar, is appreciated.
And of course, isp-control support towards a lighter server would be really cool

edit: when trying to use nginx with isp-control, does anyone know what problems this could cause or causes? and why?