I applied through an employee referral. The process took 2 weeks. I interviewed at Booz Allen Hamilton (Washington, DC) in Jan 2012
Interview
Round robin, 3-4 experts in your field will questing you for 15 min. There isn't time for chitchatting. They will just drill you on your skills. Be able to explain yourself and your skills in a short amount of time. There will be about 30 other people interviewing all at the same time, it is slightly distracting. Afterwards you listen to important people say how great they are.