Total boot time from pressing power to Firefox loaded was about 22.5 seconds, with about 5 seconds of BIOS display on a Thinkpad. Subtracting out the Thinkpad BIOS display time, that means that Ubuntu 9.04 booted into Firefox in about 17.5 seconds. I think I’m going to have a lot of fun with this hard drive. Oh, and Ubuntu 9.04 looks really interesting too.

Source:http://www.mattcutts.com/blog/ubuntu-904-boots-in-175-seconds/

With SSD's ;-)
Will buy some too...