(6 seconds save!) Enable concurrent booting allows Ubuntu to take full advantage of dual-core processors, as well as processors that hyperthread or multithread. These settings are located in your /etc/init.d/rc file:
sudo gedit /etc/init.d/rc
Look for CONCURRENCY=none and change it to:
CONCURRENCY=shell
NOTE: this possibly can cause issues with HAL for releases prior to Hardy (8.04), please see https://bugs.launchpad.net/ubuntu/+s…al/+bug/149881
