Tab Mix Plus add-on for Firefox has a handy feature where in you can switch to previous and next tabs by scrolling your mouse (with the cursor on tab bar) up and down respectively. We can achieve the same in Google Chrome using AutoHotKey. This post gives the details:
http://www.howtotuts.com/2008/09/07/how-to-switch-tabs-in-chrome-by-using-the-mouse-wheel/
http://www.howtotuts.com/2008/09/07/how-to-switch-tabs-in-chrome-by-using-the-mouse-wheel/