When iPhoto 4 first arrived in 2004, one of its touted features was improved performance when scrolling through thousands of pictures in a photo library. That was important because it did a better job of taking advantage of the hardware of the day. It was also key because as people quickly adopted digital cameras, their iPhoto libraries were growing by thousands of new images.
Our photo libraries continue to grow, and now the problem isn’t so much one of hardware performance as it is overwhelming numbers. How do you quickly locate the shots you’re looking for without having to scroll endlessly in iPhoto? Here are a few strategies for iPhoto users.
Step 1: Rate your best shots
Digital photography lets us make mistakes without paying for them in film and printing costs, but all the slightly blurry or improperly exposed photos we shoot add more cruft to our libraries. To make sorting through the large numbers of images easier, you can promote the better images in your iPhoto library by rating them with stars.
With a photo selected or enlarged to fill the viewing area, press Command and a number between 1 and 5 to add a star rating. For example, a decent shot may warrant pressing Command-1 for one star, while one that shows more promise could be immediately promoted to three stars using Command-3. You can also click a star icon in the Info pane or by choosing from the Photos -> My Rating menu, but the command-key shortcut is faster when you’re processing a bunch of images. 
Step 2: Display high rated shots
Assigning ratings to images is just the groundwork. The point of doing it is to be able to show or quickly access the good photos and hide the not-so-good ones without deleting them (you never know when a blurry shot might make a good desktop background).
To display photos based on ratings, you could enable the Search field (which in iPhoto ’11 starts as just a button by default), click the Search pop-up menu, choose Ratings, and then click the star icons. But by then it’s probably time to go to bed. Instead, press Command-F to reveal the Search field and simply type asterisks.
Entering **, for example, brings up all two-star photos. However, that displays only two-star photos, not shots rated two stars or higher. If you want to view photos rated two and three stars, separate the asterisks with a space: ** ***. 
Step 3: Sort starred images with Smart Albums
That technique is a great, speedy search method. But in the previous example, you’d still have the problem of finding all photos ranked higher than two stars. You’d have to type all combinations of star ratings, which is time consuming and, honestly, silly.
Instead, create a smart album that does the work for you. Unlike a normal album, a smart album performs a live search when you select it, so photos that match its criteria that were added after you first built the smart album do appear.
Smart albums have all sorts of uses, but here’s an example of one that shows all photos ranked 3 stars or higher shot within the last three months. Do the following:
- Choose File -> New -> Smart Album, or press Command-Option-N. (In iPhoto ’09, you could also Option-click the New Album button at the bottom of the sidebar, but that control was removed in iPhoto ’11.)
- Give the smart album a name, such as “3+ Last 3mo”.
- Using the pop-up menus, set the first criterion to read “My Rating,” “is greater than,” and then click the number of stars. Make sure to select one less than what you want, because iPhoto is looking for stars greater than the criterion, not greater than or equal to.
- Click the Add (+) button to the right to add another criterion. Change its properties to read “Date,” “is in the last,” and “3 months”.
- Click OK. The next time you select that smart album, it will show photos ranked three stars and higher within the last quarter year.
You can create as many of those general-purpose smart albums as you want, and they’ll be continually updated.
iPhoto offers more controls for narrowing the field of possibilities within your library, but these methods are the ones I turn to first when I start to process images. It no longer matters how long it takes to scroll through thousands of images, because you will have already narrowed the list down to your best shots.
[Jeff Carlson is the author of Photoshop Elements 9 for Mac OS X: Visual QuickStart Guide (Peachpit Press; 2010) and a senior editor of TidBits.]