I applied through college or university. The process took 1 day. I interviewed at Microsoft in Oct 2011
Interview
Microsoft came to our career fair at college and I gave them my resume. I heard back from them about a week later and then they send you a form to fill out for an on campus interview. Their interviews are very short. They said this at the session before the interview but that really can't be stressed enough, you get 15 minutes to make a good impression on them. They open up the interview just asking some basic questions about your background and then what projects you have worked on and then they give you some technical questions. I was given two of them. I received notice that I was declined for further interviews about a week later.
I applied online. The process took 1 day. I interviewed at Microsoft in Mar 2011
Interview
I was first contacted by email, and then was scheduled for a phone interview with someone in Human Resources. I was asked several behavioral questions, and then had to solve two open-ended problems. Somehow I got the impression that this was a "fake" interview- that is, it seemed like they just had to fill a quota for the number of interviews they conducted, while they already had hired someone for the position. I heard back the next day with a form email rejection.