4. Editing Photos
If you're anything like me, not all your photos come out perfect. In fact, lots of them are probably pretty bad, and those you can delete after import. No harm, no foul, and you didn't pay for developing.
What about those pictures that are okay, but not great? Most of the time they merely require a little work. Perhaps you need to crop out extraneous background that distracts the eye from the subject of the photo, or maybe you want to remove the red glow from your cute baby's eyes (it's the fault of the camera flash, not a sign of a demon child). iPhoto can help with those tasks.
I'm not suggesting that you whip out an image-editing application, clip your cousin's ex-husband out of the family reunion photo, and use filters that sound like alien death rays (Gaussian blur?) to make it appear as though he was never there. If you can do that, great, and iPhoto will even let you use any other image-editing application. But I can't do that, and I doubt most people can. For us, iPhoto provides the basic set of tools we need.
The main thing to remember is that there's no shame in editing photos to improve them. All the best photographers do it, and now you can do it too, thanks to iPhoto.