Comment 47 for bug 749986

You can create a file named .gtkrc-2.0 in your home directory and put the same content reported in the bug description, i.e.:

style "default-style"
{
  GtkWindow::resize-grip-height = 0
  GtkWindow::resize-grip-width = 0
}

class "GtkWidget" style "default-style"

This will disable the resize grips for all applications, without the need to use personalized launchers.