Currently I’m using Arch Linux on my desktop-machine at work. As I’m still at the evaluation phase i read trough some forums, wikis and blogs about Arch Linux.
One very interesting article I found was this one: http://www.cywhale.de/arch-linux-optimieren-booten-in-16-sekunden/
It describes how the booting time can be speeded up with some nice tricks. I did not all steps described there, but only the few changes i made saved me 19 seconds and my arch-machine now boots to the KDE logon-screen in 13 seconds.
Before the optimization: