Do mac computers need to be maintained like pc's?

I only occasionally use Disk Utility to repair permissions.

I usually get mine serviced every year or so. After a while they begin to slow down and the memory gets lost in all sorts odd places :)

No on defrag. If you run into problems, run Disk Utility.

It defrags whenever you don’t use your computer, so that’s not a problem. The only maintenance i do is to clean up my hard drive once in a while.

They automagically defreg any files over 20Megs. For the most part they simply keep working. A PC is your car that needs regular maintenance and your Mac is like the toaster. It just keeps going until it dies.