Use Symbola over Android Emoji whenever possible in Ubuntu (and possibly other distros). Save as ~/.config/fontconfig (>=12.10) or ~/.fonts.conf (<=12.04), or save to the appropriate place in /etc to apply system-wide

fonts.conf

<?xml version='1.0'?>
<!DOCTYPE fontconfig SYSTEM 'fonts.dtd'>
<fontconfig>
  <!-- Prefer Symbola over Android Emoji (or any other emoji font) -->
  <alias>
    <family>serif</family>
    <accept>
      <family>Symbola</family>
    </accept>
  </alias>
  <alias>
    <family>sans-serif</family>
    <accept>
      <family>Symbola</family>
    </accept>
  </alias>
  <alias>
    <family>monospace</family>
    <accept>
      <family>Symbola</family>
    </accept>
  </alias>
</fontconfig>