This plugin enables left and right key post navigation.
This plugin gives you an option to goto next post by pressing right key twice. Pressing Right arrow key once gives hint on what post is next. Same applies to Left arrow key. When its clicked once a simple title for next post is shown, Pressed twice takes you to previous post.
Visit my site http://jaspreetchahal.org to get help on this plugin or more precisely go to http://jaspreetchahal.org/wordpress-left-right-key-navigation-plugin