Cleanliness is next to godliness, so they say. Others might say cleanliness is next to impossible, especially when it comes to your Mac. We all collect gigabytes worth of stuff that has no use other than that it fills up hard drives - old applications, duplicate files, stuff we have forgoten about and stuff we no longer need. Fortunately, clever Mac shareware developers have this same problem and have come up with a few solutions. Take applications, for example. I download 10 to 20 a week, some for trial and some just out of curiosity. I have literally thousands of applications on my Mac but I try to keep only the ones I use and toss the rest. When you install an application, the installer places support files all over your hard drive. Each of those files takes up space and increases the risk of some future incompatibility, so it is smart to remove them when no longer needed. This task is best performed by AppZapper (appzapper.com; US$12.95). It's as simple as an application can be. Simply drag an undesired application to the AppZapper window and it will find all the support files that were installed at the same time. The AppZapper window will show you a list and you can delete them with a single click. The next step to a blissfully clean Mac is to remove duplicate files and folders. I've amassed hundreds of duplicate photos, songs, e-mails, addresses, even applications and installers. These oversight accumulations can account for many gigabytes of space on your hard disk and cause you to think you need a new Mac when you don't. The secret here is an application called Tidy Up ( www.hyperbolicsoftware.com/TidyUp.html ; US$30), which can find duplicates based upon any criteria. It can also locate similar files that were modified days apart. Want to save the old one or the new one? You choose and Tidy Up will clean out the rest. Tidy Up will also find files based on how large they are. Want to find out which ones are taking up the most space on your computer? Just ask Tidy Up and you'll get a report. This is where you discover that editing a movie saves huge files that are of no use once your video is complete. Mac users download all kinds of things. Years of having no Mac viruses lets us indulge in this seriously bad habit. But because an over-full hard drive can be as data damaging as a malicious piece of code, I recommend practising safe Mac-ing. The most clever tool developed for this is Hazel ( www.noodlesoft.com/hazel.html ; US$16). Hazel is like a maid who cleans up after you. You tell your browser to download everything to a folder on your desktop and Hazel will dispose of it after you are finished. It has a list of rules that it applies to everything in a defined space, so that an application you downloaded to try out will be deleted if you don't open it within a week. Hazel works on whatever folders you tell it to and re-files items based on where they came from or when they were edited. It can even be programmed to empty the rubbish bin, returning your Mac to its optimum state of cleanliness and perhaps ever closer to that new-Mac state of godliness.