I read with envy that the author of powertop (which I blogged about earlier) and some other blokes have managed to make Fedora boot up in 5 seconds. In comparision, my boot time is painfully slow but it's still faster than what most other Fedora users have to suffer through and certainly a lot faster than Vista and XP boot times.
I achieved this by simply disabling a lot of services that I don't use or don't like. SELinux is at the top of that list of don't likes. Sendmail is another example of a daemon that never gets started on my desktop. One service that I had forgotten to disable setroubleshootd . That's the first thing I did after reading that article.
Some of the services that do get started are in the rc.local file, it makes things a lot faster. Most of the services have elaborate startup scripts in /etc/init.d/ aren't really aren't needed. For example you can just start mysql anytime by typing mysqld_safe you don't need a 152 line script for that.