Generate SSH keys if you don't have them.

mac

@@ -1,11 +1,16 @@
 #!/usr/bin/env bash
 
+echo "Checking for SSH key, generating one if it exists ..."
+  [[ -f ~/.ssh/id_rsa.pub || -f ~/.ssh/id_dsa.pub ]] || ssh-keygen -t rsa
+
 echo "Copying public key to clipboard. Paste it into your Github account ..."
-  cat ~/.ssh/id_rsa.pub | pbcopy
+  [[ -f ~/.ssh/id_dsa.pub ]] && cat ~/.ssh/id_dsa.pub | pbcopy
+  [[ -f ~/.ssh/id_rsa.pub ]] && cat ~/.ssh/id_rsa.pub | pbcopy
   open https://github.com/account/ssh
 
 echo "Installing Homebrew, a great OS X package manager ..."
   ruby -e "$(curl -fsSL https://gist.github.com/raw/323731/install_homebrew.rb)"
+  brew update
 
 echo "Installing git for version control ..."
   brew install git

ubuntu

@@ -1,7 +1,11 @@
 #!/usr/bin/env bash
 
+echo "Checking for SSH key, generating one if it exists ..."
+  [[ -f ~/.ssh/id_rsa.pub || -f ~/.ssh/id_dsa.pub ]] || ssh-keygen -t rsa
+
 echo "Copying public key to clipboard. Paste it into your Github account ..."
-  cat ~/.ssh/id_rsa.pub | xclip
+  [[ -f ~/.ssh/id_dsa.pub ]] && cat ~/.ssh/id_dsa.pub | xclip
+  [[ -f ~/.ssh/id_rsa.pub ]] && cat ~/.ssh/id_rsa.pub | xclip
   open https://github.com/account/ssh
 
 echo "Using apt-get to install OS packages so let's update it first ..."