How to enable alt+right click to resize window [duplicate]
Put this in a script and run it:
#!/bin/bash
gconftool-2 -s -t bool /apps/metacity/general/resize_with_right_button true
gsettings set org.gnome.desktop.wm.preferences resize-with-right-button true
The gconftool-2 line is for GConf based systems, and gsettings is its newer replacement.