Oh heck yes. To be fair, iPhoto doesn't have the photo editing capabilities of, say, Adobe Photoshop, but then again it's also not hundreds of dollars and incredibly complicated to use either. In particular, for snapshots the edit tools are more than enough to fix what likely ails your photos right now.

There are two basic approaches you can take, actually: you can let iPhoto do the work, or you can do it yourself, tweaking and fiddling with enough sliders to make even Dr. Frankenstein happy. I'll show both, so you can see how they compare.

First off, here's the original photo I'll be working with, a behind-the-scenes photo I took of the amazing Cirque du Soleil show "O":

It's a pretty cool photographic composition, but the photo itself is too contrasty and it's hard to see any details in the shadow. Time to let iPhoto help us fix it!

If you click on the "Edit" button, you'll find that the usual tools shown along the bottom change to:

To start, click on the "Adjust" button, which brings up a rather alarmingly complex window:

Here's the good news: if you just want to mess around, you'll find that iPhoto automatically saves your original so there's no way to trash the original. So play a little bit!

Okay, you'd rather stay focused? I can understand that. When I'm looking at fixing or touching up photographs, I start by looking at the color distribution graphic "Levels" on the top. A good photograph (generally) has colors from across the spectrum represented, but as you can see here, the right side has no red, green or blue showing up.

My first tweak, therefore, is to simply drag and move the little pointer below the Levels graph so that the top range is shifted to where the colors are present, rather than where they're not (or a bit further even, depending on your tastes):

The result is a quick improvement in things:

Not too hard, was it? Turns out that there's a bit more we do to tweak this picture, recognizing that the blacks are pretty muddy in even the adjusted photo: there are no details on the performers' black pants, for example.

To adjust that, we need to look a bit lower down on the Levels window, down to where it says "shadows". This I adjust to taste: don't go too far with this tweak (or any, for that matter) because you'll blow out the pic and end up with something too contrasty and too grainy (due to the processing it's doing):

Here's the further improvement to the picture:

That's the manual way and I know that I can sit and fiddle with things for quite a while before I'm satisfied with the results.

Sometimes, however, you want to move quickly and let iPhoto do the work, trusting its algorithms to adjust and tweak everything "good enough" for your needs. To do that, I'll back up to the original picture (Ctrl-click on the image and one of the pop-up menu options is "Revert to Original". That's what I did) and click on "Enhance" on the edit tool bar.

The results? Not bad, not bad:

Which path you choose is up to your time, enthusiasm and how much you trust your own eye. Either way, however, I hope you can see that iPhoto has some pretty cool capabilities, of which I've only scratched the surface.