Whenever we explore someplace new -- a new island, a new continent, a new cave, a new world -- there's a necessary activity that explorers must perform before they can sensibly tell the world about their discoveries: name things. Instead of discussing "that crater up there" or "the ridge that goes from such-and-such a latitude and longitude to this other location," we apply formal names to features worth discussing. Rosetta's recent pioneering exploration of asteroid (21) Lutetia has now resulted in the assignment of names to 36 of its features:
These names riff on the asteroid's name, Lutetia, which was the name of the Roman town on the site of the city now known as Paris. Lutetia's craters are named for cities of the Roman Empire and adjacent parts of Europe at the time of Lutetia (52 BC - 360 AD); Lutetia's regiones are named for Hermann Goldschmidt, the discoverer of the asteroid Lutetia, and provinces of the Roman Empire at the time of the town Lutetia; and other features are named for rivers of the Roman Empire and adjacent parts of Europe at the time of Lutetia.
The USGS page's list of categories for naming features on planets and satellites is a list of all the worlds we've been close enough to that we can see them as places, with geography, instead of just being wandering points of light. (I'm not sure why Itokawa is not mentioned.) I hope to see this list continue to expand! And I'll note that they've anticipated Dawn's mission at Vesta by already assigning themes to several categories of features that we haven't even seen at Vesta yet, but will, soon. Vesta's craters will be named for vestal virgins, people associated with vestal virgins, and famous Roman women; Vesta's regiones will be named for Heinrich Olbers, the discoverer of Vesta (I guess they'll have to expand this category if they want to assign a name to more than one "regio"); Vesta's dorsa will be named for scientists who have contributed to the exploration and study of Vesta; and other features will be named for places associated with vestal virgins.
Want to know more about what regiones, dorsa, and other features are? Here's a glossary from the USGS.