I come from a Windows background where I needed external utilities to do most maintenance items. Disk defrag, virus scan, spy ware etc. I have been running Mac OSx for over 3 years and have never invested a dime into any such program. I just read an add of Mac Keeper, and my windows background says I need this, my mac background says it is a waste of money. Is anyone using any such utility program and are they really worth the money? What do they do for you? Also can anyone explain why I need to defrag on Windows regularly (weekly) and never seem to do this on my Mac? I am not complaining by any means I love not spending money on things I do not need but I am curious as to why the differenece.