Comment 3 for bug 1128516

Fixed in version 0.2.5:

indicator-notifications (0.2.5-0~ppa~quantal) quantal; urgency=low

  * New upstream release.
    - Add GSettings support:
      + "hide-indicator" - show/hide the indicator (LP: #1128516)
      + "max-items" - maximum number of notifications to display
  * debian/patches/eavesdrop-on-bus.patch:
    - Dropped, included upstream.
 -- Jason Conti <email address hidden> Sun, 17 Feb 2013 22:52:59 -0500

Should build and be available on the PPA in a couple of hours. You can hide the indicator with:

gsettings set net.launchpad.indicator.notifications hide-indicator true

and show it again by replacing true with false.