Automatically login to GNOME and KDE

If you want to login without entering your password at boot up, you can do the following changes to your system.
FOR GNOME(UBUNTU) users:
For Ubuntu 10.04 (Lucid Lynx)
1. Load the Gnome Administration utility by clicking on System -> Administration -> Login Screen Settings
2. Unlock the window by hitting the unlock button (you will be asked for the administrator password)
3. Enable the checkbox for Log in as <> automatically (Select your User Name from the drop-down list of users).
FOR KDE(KUBUNTU) users:
1. K–>System Setting-> Login Manager.
2. Click on the Administrative Mode.
3. Enter your password when prompted.
4. Click on the Convenience tab and check the Enable Autologin checkbox option.
5. Select the user who would be logged in automatically(if there are multiple users).
Through command-line, it can be done by editing the kdmrc file and making the following changes /etc/kde4/kdm/kdmrc:
[X-:0-Core]
AutoLoginEnable=true
AutoLoginLocked=false
AutoLoginUser=bkevan
ClientLogFile=.xsession-errors

http://oddabout.com/?p=44