mod_rails/Phusion Passenger is indeed awesome - getting set up on production was a cinch, and no babysitting has been required at all... it just works.

If you use it, consider turning on global queueing for extra special goodness: http://blog.phusion.nl/2008/10/29/phusion-passenger-now-with...

Docs: http://www.modrails.com/documentation/Users%20guide%20latest...

EDIT: (Using with Apache, no experience using nginx)