The process took 2 weeks. I interviewed at Citi (New York, NY) in Oct 2008
Interview
Very behavioral-heavy. Interviewers are usually mean and will do "stress-tests" as well. Be prepared to show humility, your experiences working in teams, and why you are interested in a specific line of business. Citigroup hiring consists of an interview on campus (may be with one or two people), a superday that has tons of interviews. Be nice. Don't be mean.