Installing the gestures requires first switching to the development channel, modifying your Google Chrome shortcut to include the
--enable-extensions parameter, and then heading over to the download page to install the extension (by simply clicking on the ChromeGestures.crx link).
Once you've installed the extension and restarted the browser, you should be able to hold down the right mouse button and swipe the mouse right or left to navigate back and forward, Down -> Right for a new tab, or even up to search with the selected text. If you get stuck, you can use Up -> Right -> Down -> Left -> Down to open up the help file, or you can do Up -> Down to open the options dialog and tweak the sensitivity. If you're a big fan of mouse gestures, this is definitely worth the effort of getting it installed.