In the past few weeks as an offshoot of it's Lunar mapping mission, the Lunar Reconnaissance Orbiter has been taking detailed images of the Apollo landing sites of 1969-72. There is a backgrounder from stuff here, with a really nice summary at Bad Astronomy here.
Here is the LRO shot of the second landing site (Apollo 12, November 1969). You can see the footprints left by astronauts Pete Conrad and Alan Bean as they conducted their explorations (picture credit NASA, click to enlarge):
And here is Pete Conrad making some of those footprints as he investigates the unmanned Surveyor 3 probe that preceded the astronauts by a couple of years (picture credit NASA, click to enlarge):
They are awesome because they are the most basic of human calling cards, and they on another world. And since there is no weather on the moon, they will be there essentially forever if left undisturbed (Transformers and Independence Day Aliens notwithstanding).