Apple provides many great video tutorials online to help users get the most out of their Macs. Included in those tutorials are several about gestures in iPhoto '11. Here are a few more gestures to help supplement those.
Courtesy of curious Mac OS X Hints user tchenj, these hints work with newer trackpads that support multitouch gesturing. I checked out each hint using iPhoto '11 on a 2010 MacBook Pro. So, if you meet the requirements, open iPhoto, select a photo, and click Edit in the toolbar on the bottom of the iPhoto window.
Note: Before you get started, you will also need to be sure multitouch gestures are enabled in System Preferences. Open System Preferences and click on Trackpad. Any gestures you will want to do should be checked here.
If you want to be able to straighten your photographs using just you trackpad, simply anchor one finger on the trackpad, then rotate another finger around it. This works going right (to drop the right side of the picture) or left (to drop the left side of the picture). Straightening your photographs is one of the best ways to make a landscape shot look really great.
Several variations of gestures can be used while cropping your photograph. First, select whether or not you want your crop to be constrained (relative to the dimensions or shape you select). If you do not need (or wish) to constrain your crop, use the pinch/open method to create your crop.
I have found that the best technique is to anchor one of your fingers in the corner of the trackpad that corresponds with the corner of the crop you wish to keep, then move the other finger to form the complete square.
If you have the shape of your rectangle, but it's not in the right spot of your photo, put two fingers on the trackpad and drag the crop box around your photo until you find the correct location.
Once you've got your crop outlined, press Return and your photo will be cropped.
Fix Red-Eye & Retouch Mode
Use the pinch gesture to zoom in on your photograph while fixing any red eyes. Getting in close can dramatically improve the accuracy of the red-eye reduction tool. Placing two fingers on the trackpad allows you to navigate around your photograph.
And, although it's not really a trackpad trick, pressing Shift while in edit mode will give you a preview of your original photograph, so you can see how far you've come. Got any great tricks or tips for the Mac? Send me a message or leave a comment!