I have been setting up some sites on nginx today (moving from an apache server) and have been pretty happy with how an Apache rewrite rule like:

RewriteRule /foo/([0-9]+)/ /foo.cfm?id=$1

Can be done in nginx like this:

rewrite /foo/([0-9]+)/ /foo.

I've been playing around with Nginx web server over the past few days, its a great light weight web server, ideal for VPS's or smaller Amazon EC2 instances where resources are not as abundant.