Steps to using this overlay: 
1) Make a directory for the overlay. The most popular way to add extra overlays is to put them in the /usr/local/overlays directory, so for this example I wil use: /usr/local/overlays/nx 
 
2) Edit your make.conf file and add this directoy to your overlay line: 
 PORTDIR_OVERLAY="/usr/local/portage /usr/local/overlays/nx" 
 You can have as many overlays as you want to have to keep things separate. I have 4 overlays. :P This is for reference. 
 
3) cd to the new overlay directory, here it's: 
 cd /usr/local/overlays/nx 
 
4) Type: 
 svn co http://svn.gnqs.org/svn/gentoo-nx-overlay/testing/net-misc
 svn co http://svn.gnqs.org/svn/gentoo-nx-overlay/testing/eclass
 now you can emerge any file you want to. :) 

Whenever the overlay is updated:
5) To update your overlay, cd to it and type: 
 svn up