Remember way back when you were a college freshman and thought it was cool to post embarrassing photos? Okay, maybe not; but did you ever have friends who thought it was cool, and some of their photos are about you?
If you're nearing the sober (and sobering) age of graduation and job-hunting, you'll probably want to do some cleaning up on your Facebook page. Heck, don't stop with photos--look for stuff you might have written or posted that could give an employer the wrong idea of how you'll fit in with a more conservative group than you're used to hanging with in college. (Religious views, politics, snark-fests and the like.)
Here's a link to a great "how to" article, complete with step by step directions and screenshots to help you find the privacy-control goodies that Facebook keeps moving around.
(I think Facebook must have a strategy--drastically change and move the privacy controls every few months, sort of like grocery stores rearrange their stock to force consumers into looking at everything, rather than just the stuff they want to buy, in places where they know to find it. More need to clean up = more "visits" to the Facebook website.)