Multiple Homebrew sources

Today I decided I wanted to install okular from kde mac project... At first I tried a search via brew search okular and discovered it's not in the official brew git repo... Not to worry, http://community.kde.org/Mac#Installing_using_Homebrew lists a repo that has forked the official repo. But how to get homebrew to install from that repo instead of the official... Well it's all based on git so:

git remote add kde git@github.com:somekool/homebrew.git
git fetch kde
git branch --list --remote
  kde/gh-pages-remi-prev
  kde/homebrew/master
  kde/kde_on_brew/master
  kde/my_own_master
  origin/master
git checkout kde_on_brew/master
brew search okular
  okular
brew install okular

Once the install is done, to change back you can just do:
git checkout master


And thats it ;)