When waking from suspension or hibernation, Ubuntu prompts the current user to unlock the screen by entering their password. You might want to disable this prompt if you want your laptop to be ready to use faster, and don’t need the extra security.
In previous versions of Ubuntu, the lock screen after waking could be disabled in the screen saver settings. In Ubuntu 11.10, the new version of GNOME has changed how this works. GNOME no longer provides any configuration option for this behavior [bug report]. The best workaround seems to be to disable the lock screen entirely, which will not only disable the lock screen after suspend, but also disable the lock screen entirely.
Open a terminal and run this command to disable the lock screen:
gsettings set org.gnome.desktop.lockdown disable-lock-screen 'true'
Running the command again with true changed to false will reverse the change:
gsettings set org.gnome.desktop.lockdown disable-lock-screen 'false'
Hopefully either Ubuntu or GNOME will bring back an option for this in a future version.