Is Disk Fragmentation a Problem for Macs?

I've always been told that a Mac doesn't need defragmenting because it does it all for you. I've changed my mind however after reading this article...

"OS X does a great job at minimizing file fragmentation by rewriting files in contiguous space when a file is opened, is under 20MB and contains more than eight fragments. This works quite well to prevent heavy file fragmentation, but what it doesn’t prevent is free space fragmentation."

I did some more researching about programs to use and who uses them, come to find out that a lot of people degrag their Macs including "the Apple folks" in CA!

Click Here to read the full article I mentioned above. It covers more info about defragmenting a Mac and lists several programs you can use. The program I ended up using is iDefrag ($30) I've been really happy with how well and fast it has worked!