I don't know about the rest of you, but one thing that I really don't like about the inbuilt disk defrag software is the lack of info as to what is going on. Back in the Win95 days (I think) the defrag software had all those little boxes that moved around with different colours etc, and gave you an idea it was upto something.

So, quick search on Google and  came across AusLogics Disk Defrag, which is fast and free (for personal use), They also do a screensaver version, and various other tools optimisation tools.

Looking for something different, then go check out there website, http://www.auslogics.com/