B.S. in sociology with a concentration in ethnic and race relations v.s. B.S. in urban and community studies?

First, keep in mind that the degree you choose will not have nearly as big an impact on your future as you think. What is important is to study hard, get good grades and pursue things that interest you. So the question is a lot simpler than you think. Choose which one you really think you will be more interested by, because neither is going to drastically affect your life path. Second, sociology does not generally involve doing "community work" although a lot of people who are interested in community-based work study sociology. As I'm sure you know, sociology is about studying the trends of societies and societies as organisms; not about changing or fixing societies. That said, there are some sociologists who believe that there can be a hybrid of both; but unless you are in a progressive sociology program, your studies will probably drier than you expected, although it will certainly ask some intriguing questions. When it comes down to it, when you are examining a social problem, like high teen pregnancy rates for example, are you more interested in designing programs to help pregnant teens and reduce teen pregnancies, or are you more interested in studying the lifestyles and backgrounds of pregnant teens to determine what the origin/reasons for the problem are? If the former is your answer, maybe a Urban/Community Studies would be better, or maybe Social Work. If the later, consider Sociology.