Select your images from Finder and then right- or Control-click on the grouping. If you’d like a different way to do the same thing, you can also use the contextual menu. When you’re ready to get out of this mode, just tap the Escape key twice. Then use the Index Sheet icon to return to the view of all the files. To enlarge a particular image, just click it. Success! Your entire screen will fill with thumbnails from that folder, making it easy as pie to choose what you’re looking for. It looks like a grouping of four squares: Once the slideshow starts, click on the Index Sheet icon on the player controls that appear. What that’ll do (unsurprisingly) is take you into a slideshow of all the images you’ve selected, which is great but not what we want.
You have to hold down the Option key to make this menu option appear. This is the keyboard shortcut for File > Slideshow Items. Anyway, hit Command-A or choose the menu item Edit > Select All once you get there, and then hit Option-Command-Y. This tip will work on any file type, really, but I don’t know how exciting it would be to see a screen full of text files.
To check out this very cool feature, go to any folder full of pictures on your Mac.
This’ll be helpful both for you designer-types out there who have tons of pictures and for those of us who don’t really do anything productive, ever.
If you’ve got the same issue (or if you have folders full of images for, you know, actual work), Mac OS X has a built-in way to view all of the files in a folder at once using Quick Look. I don’t want those files in iPhoto, but it really is a pain to go through them one at a time when I’m looking for an exciting new backdrop to use on my Mac. I have several folders on my Mac filled with potential desktop backgrounds and other various images I’ve collected.