How to change window border thickness in Ubuntu 10.04 (Gnome)

prompt%> sudo vi /usr/share/themes/Human/metacity-1/metacity-theme-1.xml

Change following values to 5 or higher:
<distance name="left_width" value="3"/>
<distance name="right_width" value="3"/>
<distance name="bottom_height" value="3"/>

Enjoy!