Over the years I've gathered a number of pictures of my ancestors. While I'll never get tired of looking at them, I've also found another very interesting way to use photos -- You can crop head shots out of your pictures and do some great things with them.
First, get digital scans of all your family history pictures. I prefer .jpg format unless I am going to be printing and framing them for my wall -- then I'll use a .tif format. If you have Windows, you will probably have the Microsoft Office Picture Manager utility. Open a photo in the utility, select "Edit Pictures" and "Crop". After positioning the borders where you want them, click "Ok" and save the head shot. I like to give it the name of the person, and append their age at the time of the photo. place the headshot in the documents folder you've designated for that family.
After you've saved the headshot, select "Edit" and "Undo Crop". Then repeat for the other people in the picture.
Here's where the fun starts. You can now make a slide show for an individual, progressively showing how they looked throughout their life. You can also add the head shots to your family history software, and they'll display in reports and summaries.
It's also neat to open a folder and see all the faces of the people you're researching.