I applied online. The process took 1 day. I interviewed at PSB Insights (New York, NY) in Jan 2010
Interview
Interview with HR and analyst. Quick and mainly about fit in the company. Analyst who interviews prospective interns and employees enjoys grilling people. Don't let them intimidate you since a majority of all the skills can be learned on the job. However I recommend seriously considering the offer if they do extend one to you.