You can get 3rd party tools to configure this if you want. Use something like BetterTouchTool if you want to configure a gesture to fire up GMail. Right now I have a 3-finger swipe up for copy, and 3-finger swipe down for paste. I also have a 4-finger gesture for switching between tabs in google chrome.
However, I think there's probably a limit on how many gestures you can keep in your head, it's a lot easier remembering keyboard shortcuts than gestures. I can probably only keep track of five different gestures per app, but I'm sure I can probably recall at least 20 different keyboard combos when I use a tool like emacs.
