I know this may sound absurd but my laptop has Xubuntu Saucy with 4GB RAM. I decreased swapiness from 60 to 7 but now applications take more time to launch and I see disk i/o before the application window appears. This is particularly the case for Thunar and the terminal. Before changing swapiness, the launch of such applications took no time.
Here are the lines in sysctl.conf: