Make Gnome Panel autohide 100%

Setting my netbook's top and bottom Gnome panel to autohide still leaves some pixels visible.

# Hide top panel completely
gconftool-2 --set --type integer /apps/panel/toplevels/top_panel_screen0/auto_hide_size 0

# Hide bottom panel completely
gconftool-2 --set --type integer /apps/panel/toplevels/bottom_panel_screen0/auto_hide_size 0

# Access configurations through GUI
ALT-F2 > "gconf-editor" > apps > panel > toplevels > top_panel_screen0 > auto_hide_size > 0

ref:
http://ubuntu-tutorials.com/2009/09/21/completely-hide-gnome-panel/