Reducing CPU frequency in UBUNTU

Seems that when installing UBUNTU in some machines. The setting for the CPU will be set for maximum performance. This tends to overheat the machine. One fix for this:

$ sudo [gvim or any text editor] /etc/rc.local

This will open the file and accept modifications to it:

#############################################
#!/bin/sh -e
#
# rc.local
#
# This script is executed at the end of each multiuser runlevel.
# Make sure that the script will “exit 0″ on success or any other
# value on error.
#
# In order to enable or disable this script just change the execution
# bits.
#
# By default this script does nothing.
for cpu in /sys/devices/system/cpu/cpu?/cpufreq/scaling_governor; do
echo -n powersave > $ cpu
done
exit 0

#############################################

Add the 3 shaded lines and then reboot.

How to avoid typing a password for the default keyring for wireless after booting Ubuntu every time

After booting an Ubuntu machine, you are asked to unlock the default keyring for some wireless connection, the simple solution to avoid this:

1. Edit the wireless connection (Right-click the "Network Manager" icon on the panel at the top-right corner of the screen and click "Edit Connections.", Click the "Wireless" tab at the top of the Network Connections window, Select the wireless connection by clicking its name in the list, Click the "Edit" button)
2. Click the "Available To All Users" checkbox at the bottom of the connection window.

Unfortunately I didn't find an equally effective solution using the shell commpand prompt. 

(This recipe was found in this web-page: http://thanhsiang.org/faqing/node/117#comment-797)