In Mac OS X, if you want more info on your files than the standard icon view provides (after all, it just gives you the file’s name in icon view)? Then turn on Show Item Info. This adds an extra line of information below many files and folders that can be very useful. For example, now not only do you get a folder’s name, but just below the name (in unobtrusive light-blue, 9-point type), you’ll see how many items are in that folder.

If the file is an image, the Item Info shows you how big it is. MP3 files show how long the song is. To turn on Item Info for your current Finder window, press Command-J to bring up its View Options. Then turn on the checkbox for Show Item Info. If you want to show the item info for every window (globally), then choose the All Windows button at the top of the dialogue window.

With Mac OS X, you can open many files in programs other than the ones in which they were created. For example, if you’d prefer to view an Adobe Acrobat PDF in the faster-loading Preview application, simply select the PDF file, choose Open With from the File menu in Finder, and choose the Preview application in the pull-down menu.

But what if you always want to open PDFs in Preview instead of choosing this application each time? Mac OS X offers an easy way to reassign all documents of the same type to open in the application you specify.

Let’s say you’ve saved several Adobe Photoshop files as JPEGs. In the future, you would like to open these files using Preview, rather than waiting for Photoshop to load. To reassign the default application simply select any one of these files, then go to the File menu in Finder and choose Get Info (or just select the file and type Command-I). Click the Open With disclosure triangle, if needed, to reveal a pull-down list of all the applications on your Mac that you can use to open this type of file.

Choose Preview from the list of applications, then click the Change All button beneath the application pull-down. (This button is grayed out until you select a different program than the one already assigned to open the file.) A pop-up will ask you to confirm that you want to apply this change to all documents of this type. Click Continue. Now whenever you double-click on one of these JPEGs, it will automatically open in Preview on your Mac instead.

If you want to stop anything appearing on your MAC’s Desktop, but want to keep files in the ~/Desktop directory, open Terminal and run the following:

defaults write com.apple.finder CreateDesktop -bool FALSE ; killall Finder

After that, you won’t see any icons on your Desktop – no files, no folders, no disks; just the pretty picture.

To reverse the process, run the command again, replacing FALSE with TRUE.