You can reduce the booting time in Linux, by disabling the
services, which are not being used by you.
There is a directory for each run-level in /etc. Those
are named as /etc/rc.< run-level > , where
run-level = 0~6
On most Linux distros, default run-level is 5, in Debian default
run-level is 2.
1. Go to your run-level directory /etc/rc.n
# cd /etc/rc.5
2. If you want to disable, Apache Web-Server (apache), just
you have to rename, the corresponding file my replacing 'S'
(start) by 'K' (kill).
# mv S91apache K91apache
Likewise, you can disable all the undesired services.
This procedure will make your linux not only fast,
but also secure.