It's old news, but underused. This is a life savior especially when you have to deal with software that you don't control, which spits out unoptimized assets. If you have compilophobia, use EasyEngine [0] or Centminmod [1]!
Yup Centmin Mod LEMP stack installer maintains and integrates ngx_pagespeed with Nginx installs http://centminmod.com/nginx_ngx_pagespeed.html along with handy command line shortcuts to enable and disable pagespeed via pscontrol command :)