If you find the idea of working as an archaeologist exciting, and would love to do it as a career, then you should study complimentary subjects while in college. You are going to want to have an impressive resume when applying to grad school programs. It's also a great help when applying for internships while still an undergrad. Archeology internships can be very difficult for an undergrad to get, but if you have experience with specific subjects and have shown that you are serious about the subject.
If you're looking to do any sort of field work, then geology is a very important. Archaeology field work will require working on digs that place you in all sorts of terrain. You might be on a riverbed, or high in the mountains. The more you know about the earth, the better equipped you will be when it comes time to do the delicate excavating work. It will also help you understand the subtle things that can impact a dig, such as how a riverbed would have flowed down a mountain over time, and how the particular rock formation was formed. Professors who run field digs will love that you have studied geology, so it's great when looking for internships.
Outside of actually field work, it's important to have an understanding of what it is you're searching for. You never know where in the world you might go, but you know the subject matter will be old. So, course work involving popular dig sites (Ancient Greece, Egypt, Ethiopia) are important. It would also be good to study ancient history of Central American civilizations such as the Mayan and Aztec. In addition to learning to identify the different types of art used by each culture, you will learn about the political events which shaped the time, which will impress the professors who will be setting up teams. The professor will be much more impressed if you can extemporaneously speak about, say, the Peloponnesian war when you identify a Athenian vase circa the 5th century, then to just say it's a piece of 5th century Greek artwork.
Native American Studies
One of the most important areas to familiarize yourself with is Native American Studies. This is really important because many of the digs you will be taking part of are located in the United States or northern Mexico. While you might get onto a team heading to Egypt, it's much more likely you will find yourself examining one of the many important archeological sites in North America. Native American history is complex and a fascinating subject to learn about. You will learn about the differences between the Southwest Tribes (Apache, Yaqui, Navajo, etc.) and Great Plains tribes (Blackfoot, Cheyenne, etc.) and other regions (Pacific, Great Lakes tribes). This will help you learn about their migratory patterns, who were hunters who ranged far and wide, who were farming tribes. You will also learn about their housing (for example, not all Native tribes use the famous Teepee; some built cliff dwellings or hogans), which is important when excavating sites.