What are the differences between anthropology and sociology?

In the past, the main difference used to be the fields of interests. Sociologists studied "us", meaning primarily urban, western societies, whereas Anthropologists studied "them", meaning small tribes, colonized peoples and the like.

In our days, the lines between the disciplines has blurred. The main difference seems to be methodical, as sociologists prefer a quantitative approach, with tools like polls, statistics, mass interviews etc, where anthropologists prefer a qualitative approach, meaning in-depth interviews and participatory observation.

One possible understanding of these differences is the two disciplines' respective levels of analysis. Sociology tends to look at a society and see its institutions and structures as of prime importance, driving and creating changes. Anthropology, while not necessarily different, has more of a sense of the way a culture can change internally, through the decisions of its members.

A short attempt at an answer to a complex question.